Compound and method of producing organic semiconductor device

ABSTRACT

A method of producing an organic semiconductor device is provided in which a layer composed of an organic semiconductor having excellent crystallinity and orientation in a low-temperature region can be formed, and the device can be produced in the air. The method includes forming a layer composed of an organic semiconductor precursor on a base body and irradiating the organic semiconductor precursor with light, wherein the organic semiconductor precursor is a porphyrin compound or an azaporphyrin compound having in its molecule at least one of the structure represented by the following general formula (1) or (2):

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a novel compound and a method ofproducing an organic semiconductor device.

2. Description of the Related Art

Development of a thin film transistor using an organic semiconductor hasgradually become active since the latter half of 1980s. In recent years,the basic performance of the thin film transistor using the organicsemiconductor has exceeded the basic performance of a thin filmtransistor using amorphous silicon. Each of organic semiconductormaterials often has a high affinity for a plastic substrate on which asemiconductor device such as a thin-film field effect transistor (FET)is formed. Therefore, the organic semiconductor materials are each anattractive material for a semiconductor layer in a device of whichflexibility or lightweight property is desired. In addition, some of theorganic semiconductor materials can each be formed into a film by theapplication of a solution or a printing method. The use of any suchmaterial enables a large-area device to be produced simply at a lowcost.

Examples of the organic semiconductor materials heretofore proposedinclude the following materials. First, the examples include acenesdisclosed in Japanese Patent Application Laid-Open No. H05-55568, suchas pentacene and tetracene. The examples further include phthalocyanineseach containing lead phthalocyanine disclosed in Japanese PatentApplication Laid-Open No. H05-190877, and low-molecular-weight compoundssuch as perylene and a tetracarboxylic acid derivative of perylene. Inaddition, Japanese Patent Application Laid-Open No. H08-264805 proposesan aromatic oligomer typified by a thiophene hexamer referred to asα-thienyl or sexithiophene, and, furthermore, polymer compounds such aspolythiophene, polythienylene vinylene, and poly-p-phenylene vinylene.It should be noted that most of them are described in Advanced Material,2002, 2nd issue, p. 99 to 117.

Characteristics demanded when a device is produced by using any suchcompound in the semiconductor layer of the device, such as a non-linearoptical characteristic, conductivity, and a semiconductorcharacteristic, largely depend on not only the purity of the compound asa material for the layer but also the crystallinity and orientation ofthe material.

By the way, most of low-molecular-weight compounds (such as pentacene)in each of which a π-conjugated system is expanded has highcrystallinity, and is insoluble in a solvent. Accordingly, a thin filmcomposed of each of those compounds is formed by employing a vacuumdeposition method in most cases. Pentacene is known to show high fieldeffect mobility, but has involved the following problem: pentacene is soinstable in the air as to be apt to be oxidized and to deteriorate. Inaddition, when employing vacuum film formation such as a vacuumdeposition method, the merit of an organic semiconductor material isreduced such that a large-area device can be produced from the materialat a low cost.

On the other hand, an organic semiconductor using a π-conjugated polymercan be easily formed into a thin film by, for example, a solutionapplication method in many cases. Therefore, the applied development ofan organic semiconductor film using a π-conjugated polymer has beenadvanced because the film is often excellent in moldability (“JapaneseJournal of Applied Physics” by the Japan Society of Applied Physics,1991, vol. 30, p. 610 to 611). The arrangement state of molecular chainsin the π-conjugated polymer is known to have a large influence onelectrical conductivity. Similarly, it has been reported that the fieldeffect mobility of a π-conjugated polymer field effect transistorgreatly depends on the arrangement state of molecular chains in asemiconductor layer (“Nature”, Nature Publishing Group, 1999, vol. 401,p. 685-687). However, the arrangement of molecular chains in theπ-conjugated polymer is performed during the period from coating with asolution to drying of the solution, so the arrangement state of themolecular chains may vary to a large extent owing to a change inenvironment and a difference in coating method. Accordingly, the fieldeffect mobility varies depending on a condition under which the solutionis applied, so it may be difficult to stably produce the transistor.

In addition, in recent years, an FET has also been reported which uses afilm obtained by: forming a thin film composed of a soluble precursor bycoating; and converting the precursor into an organic semiconductor byheat treatment or irradiation with light (J. Appl. Phys. vol. 79, 1996,p. 2136, Japanese Patent Application Laid-Open No. 2004-266157, andJapanese Patent Application Laid-Open No. 2004-221318). Pentacene andporphyrin have been reported as examples in which a precursor isconverted into an organic semiconductor by heat treatment. However,problems have been raised in that the conversion of the precursor intoporphyrin or pentacene requires treatment at high temperature, andeliminated components having large mass must be removed bydecompression. Pentacene is cited as an example in which a precursor isconverted into an organic semiconductor by irradiation with light. Inthis case, treatment at high temperature is not required, but a problemis raised in that irradiation with light must be performed in an inertatmosphere.

Further, a dimer of pentacene is a known example of an organicsemiconductor into which a precursor can be converted with either ofheat and light. However, the dimer has involved the following problem:[4+4] optical dimerization is employed for the dimerization ofpentacene, so a skeleton to which the dimer is adaptable is limited(Japanese Patent Application Laid-Open No. 2004-107216).

Further, in Tetrahedron Letters 45 (2004), p. 7287 to 7289, a materialhaving a skeleton represented by the following general formula (12)(hereinafter referred to as “SCO skeleton”) is described as a pentaceneprecursor, and it is described that the pentacene precursor is convertedinto pentacene by heating. However, in Tetrahedron Letters 45 (2004), p.7287 to 7289, it is not described that the conversion of the pentaceneprecursor into pentacene proceeds also with light.

In addition, in Advanced Materials 15, No. 24 (2003), p. 2066 to 2069 itis described that a pentacene precursor is converted into pentacene byheating. However, in the document, it is described that irradiation withlight only results in the polymerization of a substituent of theprecursor, so a bicyclo skeleton is maintained, and the conversion ofthe precursor into pentacene does not occur. The foregoing indicatesthat an N-sulfinyl group represented by a general formula (14) isconverted with heat, but not converted with light:

where R₄₄ represents a linear or branched alkyl, alkenyl, alkoxy,alkylthio, alkyl ester, or aryl group, a hydroxyl group, or a halogenatom.

In addition, as reported in Organic Reactions Volume 52, in a skeletonrepresented by a general formula (15), irradiation with light results inthe elimination of ketene to aromatize the remainder, but heating at180° C. does not cause the elimination. From those examples, it isrealized that skeletons are very rare which undergo elimination witheither of light and heat in a low-temperature process up to 200° C.

As described above, in an FET device using an organic semiconductorcompound, an organic semiconductor layer having crystallinity andorientation has been conventionally formed through a complicated stepsuch as vacuum film formation.

Even the formation of a film excellent in orientation and crystallinityby a simple method such as a coating method has often required extremelyhigh temperature. In addition, a film that can be formed at lowtemperature has been poor in stability in the air.

SUMMARY OF THE INVENTION

That is, according to the present invention, a layer composed of anorganic semiconductor excellent in crystallinity and orientation in alow-temperature region can be formed, and an organic semiconductordevice can be produced in the air. Accordingly, an organic semiconductordevice can be easily produced by using any one of various plasticsubstrates as well as a heat-resistant substrate such as a glasssubstrate.

In addition, according to the present invention, an organicsemiconductor layer can be formed with either of heat and light, so aheat process and a light process can be alternatively employed forforming an organic semiconductor layer from one material depending onthe properties of peripheral members.

In addition, a novel compound is provided which can be used in, forexample, the afore-mentioned organic semiconductor device.

A semiconductor device obtained by a production method of the presentinvention can be utilized in, for example, a plastic IC card, aninformation tag, or a display because the characteristics of the devicevary to a small extent, and the device has high durability.

The present invention provides a method of producing an organicsemiconductor device having a layer composed of an organicsemiconductor, including: forming a layer composed of an organicsemiconductor precursor on a base body; and irradiating the organicsemiconductor precursor with light, wherein the layer composed of theorganic semiconductor precursor contains, as the organic semiconductorprecursor, a porphyrin compound or an azaporphyrin compound having inits molecule at least one of a structure represented by the followinggeneral formula (1) or (2):

where X₁ and Y₁ are each independently one selected from the groupconsisting of an oxygen atom, a sulfur atom, a carbonyl group, athiocarbonyl group, CR₁R₂, and NR₃, wherein R₁ to R₃ are eachindependently one selected from the group consisting of a hydrogen atom,linear or branched alkyl, alkenyl, alkoxy, alkylthio, alkyl ester, andaryl groups each having 1 to 12 carbon atoms, and a hydroxyl group,provided that both X₁ and Y₁ are not CR₁R₂ at the same time;

where X₂═Y₂ is represented by N═N or CR₄═N wherein R₄ is one selectedfrom the group consisting of a hydrogen atom, linear or branched alkyl,alkenyl, alkoxy, alkylthio, alkyl ester, and aryl groups each having 1or more to 12 or less carbon atoms, and a hydroxyl group.

The structure represented by the general formula (1) preferably includesa structure represented by any one of the following general formulae(3), (4), and (5).

The organic semiconductor precursor preferably includes a compoundrepresented by the following general formula (9):

where the B ring is represented by the following general formula (25) or(26), R₁₇ to R₂₂ are each independently selected from the groupconsisting of a hydrogen atom, a hydroxyl group, a halogen atom, analkyl group, an alkoxy group, an alkylthio group, an ester group, anaryl group, a heterocyclic group, and an aralkyl group, Z₁ to Z₄ areeach selected from the group consisting of a nitrogen atom and CR₆₀, andmay be identical to or different from one another, R₆₀ is selected fromthe group consisting of a hydrogen atom and an aryl group which may havea substituent, M represents two hydrogen atoms, a metal atom, or a metaloxide, and R₁₇ and R₁₈, R₁₉ and R₂₀, or R₂₁ and R₂₂ may be coupled witheach other to form the B ring;

where X₃ and Y₃ each independently represent one selected from the groupconsisting of an oxygen atom, a sulfur atom, a carbonyl group, athiocarbonyl group, CR₆₈R₆₉, and NR₇₀, wherein R₆₈ to R₇₀ are eachindependently selected from the group consisting of a hydrogen atom,linear or branched alkyl, alkenyl, alkoxy, alkylthio, alkyl ester, andaryl groups each having 1 to 12 carbon atoms, and a hydroxyl group,provided that X₃ and Y₃ are not CR₆₈R₆₉ at the same time, R₅₄ to R₅₉ areeach independently selected from the group consisting of a hydrogenatom, an alkyl group, an alkoxy group, an aryl group, a heterocyclicgroup, an aralkyl group, a phenoxy group, a cyano group, a nitro group,an ester group, a carboxyl group, and a halogen atom, R₅₈ and R₅₉ may becoupled with each other to form a five-membered heterocyclic ring or asix-membered heterocyclic ring, and n₅ and n₆ are each independently aninteger of 0 or more;

where X₄═Y₄ is represented by N═N or CR₆₇═N, wherein R₆₇ is selectedfrom the group consisting of a hydrogen atom, linear or branched alkyl,alkenyl, alkoxy, alkylthio, alkyl ester, and aryl groups each having 1to 12 carbon atoms, and a hydroxyl group, R₆₁ to R₆₆ are eachindependently selected from the group consisting of a hydrogen atom, analkyl group, an alkoxy group, an aryl group, a heterocyclic group, anaralkyl group, a phenoxy group, a cyano group, a nitro group, an estergroup, a carboxyl group, and a halogen atom, R₆₅ and R₆₆ may be coupledwith each other to form a five-membered heterocyclic ring or asix-membered heterocyclic ring, and n₇ and n₈ are each independently aninteger of 0 or more.

The organic semiconductor precursor preferably has a structure in whichthe B ring of the general formula (9) is represented by any one of thefollowing general formulae (27), (28), and (29):

where R₅₄ to R₅₉ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom, R₅₈ and R₅₉ may be coupled with each other to form a five-memberedheterocyclic ring or a six-membered heterocyclic ring, and n₅ and n₆ areeach independently an integer of 0 or more;

where R₇₁ to R₇₆ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom, R₇₅ and R₇₆ may be coupled with each other to form a five-memberedheterocyclic ring or a six-membered heterocyclic ring, and n₉ and n₁₀are each independently an integer of 0 or more;

where R₇₇ to R₈₂ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom, R₈₁ and R₈₂ may be coupled with each other to form a five-memberedheterocyclic ring or a six-membered heterocyclic ring, and n₁₁ and n₁₂are each independently an integer of 0 or more.

The organic semiconductor precursor is preferably a compound in whichall of Z₁ to Z₄ of the general formula (9) are each represented by CH,and the B ring of the formula is represented by the general formula(27).

The organic semiconductor precursor preferably includes a compoundrepresented by the following general formula (21):

where R₈₃ to R₈₈ are each independently selected from the groupconsisting of a hydrogen atom, a hydroxyl group, a halogen atom, analkyl group, an alkoxy group, an alkylthio group, an ester group, anaryl group, a heterocyclic group, and an aralkyl group, M₄ representstwo hydrogen atoms, a metal atom, or a metal oxide, and R₈₃ and R₈₄, R₈₅and R₈₆, or R₈₇ and R₈₈ may be coupled with each other to form a generalformula (30).

The irradiation of the organic semiconductor precursor with light ispreferably performed while heating the precursor.

The crystallization promoting layer preferably includes a layercontaining a polysiloxane compound.

The polysiloxane compound preferably contains a compound having at leasta structure represented by the following general formula (6):

where R₅ to R₈ each represent any one of a substituted or unsubstitutedalkyl or alkenyl group having 1 to 8 carbon atoms, a substituted orunsubstituted phenyl group, and a siloxane unit, R₅ to R₈ may beidentical to or different from one another, and n represents an integerof 1 or more.

The polysiloxane compound preferably contains a compound having at leasta structure represented by the following general formula (7) or (8):

where R₉ to R₁₂ each represent one of a substituted or unsubstitutedalkyl or alkenyl group having 1 to 8 carbon atoms, and a substituted orunsubstituted phenyl group, R₉ to R₁₂ may be identical to or differentfrom one another, m and n each independently represent an integer of 0or more, and the sum of m and n is an integer of 1 or more;

where R₁₃ to R₁₆ each represent one of a substituted or unsubstitutedalkyl or alkenyl group having 1 to 8 carbon atoms, and a substituted orunsubstituted phenyl group, R₁₃ to R₁₆ may be identical to or differentfrom one another, r and p each independently represent an integer of 0or more, and the sum of r and p is an integer of 1 or more.

The organic semiconductor precursor is preferably heated by heating thebase body from the outside of the base body.

The formation of the layer composed of the organic semiconductorprecursor is preferably performed by applying or printing a solutioncontaining the organic semiconductor precursor on the base body.

In addition, another embodiment of the present invention is a method forproducing an organic semiconductor device having a layer composed of anorganic semiconductor, including: forming a layer composed of an organicsemiconductor precursor on a base body; and subjecting the organicsemiconductor precursor to heating and irradiation with light, whereinthe layer composed of the organic semiconductor precursor contains, asthe organic semiconductor precursor, a compound having in its moleculeat least one of a structure represented by the following general formula(12).

The layer composed of the organic semiconductor precursor is preferablyformed from a solution comprised of the compound having in its moleculeat least one of the structure represented by the general formula (12)and an organic solvent containing at least a polar solvent.

The organic semiconductor precursor preferably includes a compoundrepresented by the following general formula (13):

where the A ring represents one of an SCO skeleton represented by thefollowing general formula (12), a five-membered heterocyclic ring, and asix-membered heterocyclic ring, R₃₇ and R₄₂ are each independentlyselected from the group consisting of a hydrogen atom, an alkyl group,an alkoxyl group, an ester group, and a phenyl group, R₃₄ to R₃₆, R₃₈ toR₄₁, and R₄₃ are each independently selected from the group consistingof a hydrogen atom, an alkyl group, an alkoxyl group, an aryl group, aheterocyclic group, an aralkyl group, a phenoxy group, a cyano group, anitro group, an ester group, a carboxyl group, and a halogen atom, R₃₄to R₃₆, R₃₈ to R₄₁, and R₄₃ may be identical to or different from oneanother, R₃₄ and R₃₅, or R₃₉ and R₄₀ may be coupled with each other toform one of an SCO skeleton, a five-membered heterocyclic ring, and asix-membered heterocyclic ring, and the sum of n₁ to n₄ represents aninteger of 1 or more.

The compound represented by the general formula (13) preferably includesa compound represented by the following general formula (23).

Further, still another embodiment of the present invention provides acompound which has in its molecule at least one of a structurerepresented by the following general formula (1) or (2) and has aporphyrin skeleton or an azaporphyrin skeleton.

where X₁ and Y₁ each independently represent one selected from the groupconsisting of an oxygen atom, a sulfur atom, a carbonyl group, athiocarbonyl group, CR₁R₂, and NR₃, wherein R₁ to R₃ are eachindependently selected from the group consisting of a hydrogen atom,linear or branched alkyl, alkenyl, alkoxy, alkylthio, alkyl ester, andaryl groups each having 1 to 12 carbon atoms, and a hydroxyl group,provided that X₁ and Y₁ are not CR₁R₂ at the same time;

where X₂═Y₂ is represented by N═N or CR₄═N, and R₄ is selected from thegroup consisting of a hydrogen atom, linear or branched alkyl, alkenyl,alkoxy, alkylthio, alkyl ester, and aryl groups each having 1 to 12carbon atoms, and a hydroxyl group.

The structure represented by the general formula (1) preferably includesa structure represented by one of the following general formulae (3),(4), and (5).

The compound preferably has a structure represented by the followinggeneral formula (9).

where the B ring is represented by the following general formula (25) or(26), R₁₇ to R₂₂ are each independently one selected from the groupconsisting of a hydrogen atom, a hydroxyl group, a halogen atom, analkyl group, an alkoxy group, an alkylthio group, an ester group, anaryl group, a heterocyclic group, and an aralkyl group, Z₁ to Z₄ areeach selected from the group consisting of a nitrogen atom and CR₆₀, andmay be identical to or different from one another, wherein R₆₀ is oneselected from the group consisting of a hydrogen atom and an aryl groupwhich may have a substituent, M represents two hydrogen atoms, a metalatom, or a metal oxide, and each pair of R₁₇ and R₁₈, R₁₉ and R₂₀, orR₂₁ and R₂₂ may be combined together to form the B ring;

where X₃ and Y₃ each independently represent one selected from the groupconsisting of an oxygen atom, a sulfur atom, a carbonyl group, athiocarbonyl group, CR₆₈R₆₉, and NR₇₀, R₆₈ to R₇₀ are each independentlyone selected from the group consisting of a hydrogen atom, linear orbranched alkyl, alkenyl, alkoxy, alkylthio, alkyl ester, and aryl groupseach having 1 to 12 carbon atoms, and a hydroxyl group, provided that X₃and Y₃ are not CR₆₈R₆₉ at the same time, R₅₄ to R₅₉ are eachindependently one selected from the group consisting of a hydrogen atom,an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, anaralkyl group, a phenoxy group, a cyano group, a nitro group, an estergroup, a carboxyl group, and a halogen atom, R₅₈ and R₅₉ may be coupledwith each other to form a five-membered heterocyclic ring or asix-membered heterocyclic ring, and n₅ and n₆ each independentlyrepresent an integer of 0 or more;

where X₄═Y₄ is represented by N═N or CR₆₇═N, wherein R₆₇ is one selectedfrom the group consisting of a hydrogen atom, linear or branched alkyl,alkenyl, alkoxy, alkylthio, alkyl ester, and aryl groups each having 1to 12 carbon atoms, and a hydroxyl group, R₆₁ to R₆₆ are eachindependently one selected from the group consisting of a hydrogen atom,an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, anaralkyl group, a phenoxy group, a cyano group, a nitro group, an estergroup, a carboxyl group, and a halogen atom, R₆₅ and R₆₆ may be coupledwith each other to form a five-membered heterocyclic ring or asix-membered heterocyclic ring, and n₇ and n₈ each independentlyrepresent an integer of 0 or more.

The B ring of the general formula (9) preferably has a structurerepresented by one of the following general formulae (27), (28), and(29):

where R₅₄ to R₅₉ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom, R₅₈ and R₅₉ may be coupled with each other to form a five-memberedheterocyclic ring or a six-membered heterocyclic ring, and n₅ and n₆each independently represent an integer of 0 or more;

where R₇₁ to R₇₆ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom, R₇₅ and R₇₆ may be coupled with each other to form a five-memberedheterocyclic ring or a six-membered heterocyclic ring, and n₉ and n₁₀each independently represent an integer of 0 or more;

where R₇₇ to R₈₂ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom, R₈₁ and R₈₂ may be coupled with each other to form a five-memberedheterocyclic ring or a six-membered heterocyclic ring, and n₁₁ and n₁₂each independently represent an integer of 0 or more.

All of Z₁ to Z₄ of the general formula (9) are preferably represented byCH, and the B ring of the formula is preferably represented by thegeneral formula (27).

All of Z₁ to Z₄ of the general formula (9) are preferably represented bya nitrogen atom, and the B ring of the formula is preferably representedby the general formula (27).

The compound is preferably represented by the following general formula(21):

where R₈₃ to R₈₈ are each independently selected from the groupconsisting of a hydrogen atom, a hydroxyl group, a halogen atom, analkyl group, an alkoxy group, an alkylthio group, an ester group, anaryl group, a heterocyclic group, and an aralkyl group, M₄ representstwo hydrogen atoms, a metal atom, or a metal oxide, and R₈₃ and R₈₄, R₈₅and R₈₆, or R₈₇ and R₈₈ may be coupled with each other to form a generalformula (30).

In addition, it is possible to produce a field effect transistor as thesemiconductor device.

The present invention comprehends an appropriate combination of theabove features.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view showing a structure of a topelectrode type field effect transistor in Example 1 of the presentinvention.

FIG. 2 is a schematic sectional view showing a structure of a topelectrode type field effect transistor in an example of the presentinvention.

FIG. 3 is a UV spectrum of an organic semiconductor film produced inExample 24.

FIGS. 4( a) and 4(b) are NMR spectra of a compound from which an organicsemiconductor film produced in Example 23 is formed.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, the first and second embodiments of the present inventionwill be described in detail.

The first embodiment of the present invention provides a method ofproducing an organic semiconductor device having a layer composed of anorganic semiconductor, including: (i) forming a layer composed of anorganic semiconductor precursor on a base body; and (ii) irradiating theorganic semiconductor precursor with light; and (iii) the layer composedof the organic semiconductor precursor contains, as the organicsemiconductor precursor, a porphyrin compound or an azaporphyrincompound having in its molecule at least one of a structure representedby the following general formula (1) or (2):

where X₁ and Y₁ each independently represent one selected from the groupconsisting of an oxygen atom, a sulfur atom, a carbonyl group, athiocarbonyl group, CR₁R₂, and NR₃, wherein R₁ to R₃ are eachindependently selected from the group consisting of a hydrogen atom,linear or branched alkyl, alkenyl, alkoxy, alkylthio, alkyl ester, andaryl groups each having 1 to 12 carbon atoms, and a hydroxyl group,provided that X₁ and Y₁ are not CR₁R₂ at the same time;

where X₂═Y₂ is represented by N═N or CR₄═N, and R₄ is selected from thegroup consisting of a hydrogen atom, linear or branched alkyl, alkenyl,alkoxy, alkylthio, alkyl ester, and aryl groups each having 1 to 12carbon atoms, and a hydroxyl group.

In addition, the second embodiment of the present invention provides acompound which has in its molecule at least one of a structurerepresented by the following general formula (1) or (2) and has aporphyrin skeleton or an azaporphyrin skeleton.

Hereinafter, the respective steps possessed by the first embodiment ofthe present invention, and the second embodiment of the presentinvention will be described in detail.

Regarding steps (i) and (iii):

In step (i), a layer formed of an organic semiconductor precursor isformed on a base body.

The layer composed of an organic semiconductor precursor includes as theorganic semiconductor precursor a porphyrin compound or azaporphyrincompound having in its molecule at least one of the structurerepresented by the following general formula (1) or (2):

where X₁ and Y₁ each independently represent one selected from an oxygenatom, a sulfur atom, a carbonyl group, a thiocarbonyl group, CR₁R₂, andNR₃, wherein R₁ to R₃ are each independently selected from a hydrogenatom, linear or branched alkyl, alkenyl, alkoxy, alkylthio, alkyl ester,and aryl groups that have 1 to 12 carbon atoms and may be substituted orunsubstituted, and a hydroxyl group, provided that X₁ and Y₁ are notCR₁R₂ at the same time. Examples of the alkyl group include a methylgroup, an ethyl group, a propyl group, an isopropyl group, a butylgroup, an isobutyl group, an s-butyl group, and a t-butyl group.Examples of the alkenyl group include a vinyl group and an allyl group.Examples of the alkoxy group include a methoxy group, an ethoxy group,and a propoxy group. Examples of the alkylthio group include amethylthio group and an ethylthio group. Examples of the alkyl estergroup include a methyl ester group, an ethyl ester group, a propyl estergroup, and a butyl ester group. Examples of the aryl group include aphenyl group and naphthyl group that may have a substituent.

where X₂═Y₂ is represented by N═N or CR₄═N, and R₄ is selected from thegroup consisting of a hydrogen atom, linear or branched alkyl, alkenyl,alkoxy, alkylthio, alkyl ester, and aryl groups that have 1 to 12 carbonatoms and may be substituted or unsubstituted, and a hydroxyl group.Herein, examples of the alkyl group include a methyl group, an ethylgroup, a propyl group, an isopropyl group, a butyl group, an isobutylgroup, an s-butyl group, and a t-butyl group. Examples of the alkenylgroup include a vinyl group and an allyl group. Examples of the alkoxygroup include a methoxy group, an ethoxy group, and a propoxy group.Examples of the alkylthio group include a methylthio group and anethylthio group. Examples of the alkyl ester group include a methylester group, an ethyl ester group, a propyl ester group, and a butylester group. Examples of the aryl group include a phenyl group and anaphthyl group that may have a substituent.

It should be noted that the term “porphyrin compound” as used in thepresent invention refers to a compound having a porphyrin skeleton, andthe term “azaporphyrin compound” as used in the present invention refersto a compound having an azaporphyrin skeleton.

In addition, the concept of the term “or” used herein includes “and”, sothe phrase “A contains B or C” includes a case where A is free from Cand contains B, a case where A is free from B and contains C, and a casewhere A contains B and C.

The porphyrin compound or azaporphyrin compound having a structurerepresented by the general formula (1) or (2) preferably has a structurerepresented by one of the following general formulae (3), (4), and (5).

When an organic semiconductor precursor having as a partial structurebicyclo skeleton represented by the general formula (1) or (2) isirradiated with light (light is applied to the precursor), the bicycloskeleton undergoes a reverse Diels-Alder reaction with energy obtainedby the irradiation. Here, the term “Diels-Alder reaction” refers to anorganic chemical reaction in which a double bond referred to as adienophile is added to a conjugated diene to produce a cyclic structure.The reverse Diels-Alder reaction is a reverse reaction of theDiels-Alder reaction, i.e., a reaction in which the formed cyclicstructure is converted into a conjugated diene and dienophile. To bespecific, as shown in the following reaction formula (1) or (2), thebicyclo skeleton is converted into an aromatic ring. In conjunction withthe conversion, the organic semiconductor precursor is changed to anorganic semiconductor.

As shown in the reaction formula (1), the unit X₁═Y₁ is eliminated fromthe bicyclo skeleton represented by the general formula (1) with light.In connection with the elimination, the bicyclo skeleton is changed toan aromatic ring. It should be noted that when the unit X₁═Y₁ is aninstable structure, the unit X₁═Y₁ may be further converted into astable structure. Accordingly, X₁ and Y₁ are selected depending onwhether the unit X₁═Y₁ can be eliminated with light. X₁ and Y₁ representat least one selected from an oxygen atom, a sulfur atom, a carbonylgroup, a thiocarbonyl group, CR₁R₂, and NR₃, wherein R₁ to R₃ eachindependently represent one selected from a hydrogen atom, linear orbranched alkyl, alkenyl, alkoxy, alkylthio, alkyl ester, and aryl groupseach having 1 to 12 carbon atoms, and a hydroxyl group, provided that X₁and Y₁ are not CR₁R₂ at the same time. Examples of the alkyl groupinclude a methyl group, an ethyl group, a propyl group, an isopropylgroup, a butyl group, an isobutyl group, an s-butyl group, and a t-butylgroup. Examples of the alkenyl group include a vinyl group and an allylgroup. Examples of the alkoxy group include a methoxy group, an ethoxygroup, and a propoxy group. Examples of the alkylthio group include amethylthio group and an ethylthio group. Examples of the alkyl estergroup include a methyl ester group, an ethyl ester group, a propyl estergroup, and a butyl ester group. The aryl group is, for example, a phenylgroup which may have a substituent. When the number of carbon atoms ofR₃ exceeds 12, the molecular weight of the eliminated componentincreases, so the component remains in the produced organicsemiconductor in some cases. In such cases, a sufficient semiconductorcharacteristic cannot be obtained. In addition, the number of carbonatoms of R₃ is more preferably 6 or less.

As shown in the reaction formula (2), the unit X₂≡Y₂ is eliminated fromthe bicyclo skeleton represented by the general formula (2) with light.In conjunction with the elimination, the bicyclo skeleton is changed toan aromatic ring. It should be noted that when the unit X₂≡Y₂ is aninstable structure, the unit X₂≡Y₂ may be further converted into astable structure. Accordingly, X₂ and Y₂ are selected depending onwhether the unit X₂≡Y₂ can be eliminated with light. X₂ and Y₂ eachpreferably represent a nitrogen atom.

It should be noted that an organic semiconductor precursor having as apartial structure an SCO skeleton represented by the general formula (5)undergoes a reverse Diels-Alder reaction with either of heat energy andlight energy. To be specific, as shown in a reaction formula (3), theSCO skeleton is converted into an aromatic ring. In conjunction with thetransformation, the organic semiconductor precursor is changed into anorganic semiconductor.

Examples of the porphyrin compound or azaporphyrin compound having astructure represented by the general formula (1) or (2) includecompounds represented by the following general formula (9):

where: the B ring is represented by the general formula (25) or (26)described below; R₁₇ to R₂₂ each are selected from a hydrogen atom, alinear or branched alkyl group, alkenyl group, alkoxy group, alkylthiogroup, alkylester group, and aryl group that are substituted orunsubstituted and have 1 to 12 carbon atoms, a hydroxyl group, ahydrogen atom, a heterocyclic group and an aralkyl group, and R₁₇ to R₂₂are the same or different from each other; examples of the alkyl groupinclude a methyl group, an ethyl group, a propyl group, an isopropylgroup, a butyl group, an isobutyl group, an s-butyl group, and a t-butylgroup; examples of the alkenyl group include a vinyl group and an allylgroup; examples of the alkoxy group include a methoxy group, an ethoxygroup, and a propoxy group; examples of the alkylthio group include amethylthio group and an ethylthio group; examples of the alkyl estergroup include a methyl ester group, an ethyl ester group, a propyl estergroup, and a butyl ester group; examples of the aryl group include aphenyl group and naphthyl group that may have a substituent; examples ofthe heterocyclic ring group include a monocyclic heterocyclic ring suchas a monovalent pyridine ring, pyradine ring, pyrimidine ring,pyridazine ring, pyrrole ring, imidazole ring, pyrazole ring, furanring, thiophene ring, oxazole ring, isoxazole ring, thiazole ring,isothiazole ring, furazan ring, and selenophene ring, and silole ringthat may have a substituent, and a fused heterocyclic ring group inwhich a monocyclic heterocyclic ring and an aromatic hydrocarbon ringare arbitrarily combined and fused; examples of the aralkyl groupinclude a benzyl group, a phenylethyl group, and a phenethyl group; Z₁to Z₄ are selected from a nitrogen atom or CR₆₀, and Z₁ to Z₄ are thesame or different from each other; R₆₀ is selected from a hydrogen atomand aryl groups such as a phenyl group and naphthyl group that may havea substituent; M is not particularly limited as long as M represents twohydrogen atoms, a metal atom, or a metal oxide; examples of the metalinclude copper, gold, silver, zinc, nickel, chromium, magnesium, andlithium. Examples of the metal oxide include TiO and VO. M representsparticularly preferably two hydrogen atoms or a copper atom; each pairof R₁₇ and R₁₈, R₁₉ and R₂₀, and R₂₁ and R₂₂ are combined together toform the B ring.

where X₃ and Y₃ each independently represent at least one selected fromthe group consisting of an oxygen atom, a sulfur atom, a carbonyl group,a thiocarbonyl group, CR₆₈R₆₉, and NR₇₀, R₆₈ to R₇₀ are eachindependently selected from the group consisting of a hydrogen atom,linear or branched alkyl, alkenyl, alkoxy, alkylthio, alkyl ester, andaryl groups each having 1 to 12 carbon atoms, and a hydroxyl group,provided that X₃ and Y₃ are not CR₆₈R₆₉ at the same time. Examples ofthe alkyl group include a methyl group, an ethyl group, a propyl group,an isopropyl group, a butyl group, an isobutyl group, an s-butyl group,and a t-butyl group; examples of the alkenyl group include a vinyl groupand an allyl group; examples of the alkoxy group include a methoxygroup, an ethoxy group, and a propoxy group; examples of the alkylthiogroup include a methylthio group and an ethylthio group; examples of thealkyl ester group include a methyl ester group, an ethyl ester group, apropyl ester group, and a butyl ester group; examples of the aryl groupinclude a phenyl group and naphthyl group that may have a substituent.R₅₄ to R₅₉ are each independently selected from the group consisting ofa hydrogen atom, an alkyl group, an alkoxy group, an aryl group, aheterocyclic group, an aralkyl group, a phenoxy group, a cyano group, anitro group, an ester group, a carboxyl group, and a halogen atom.Examples of the alkyl group include a methyl group, an ethyl group, apropyl group, an isopropyl group, a butyl group, an isobutyl group, ans-butyl group, and a t-butyl group; examples of the alkoxy group includea methoxy group, an ethoxy group, and a propoxy group; examples of theester group include a methyl ester group and an ethyl ester group, apropyl ester group, and a butyl ester group; examples of the aryl groupinclude a phenyl group and naphthyl group that may have a substituent;examples of the heterocyclic ring group include a monocyclicheterocyclic ring group such as a monovalent pyridine ring, pyradinering, pyrimidine ring, pyridazine ring, pyrrole ring, imidazole ring,pyrazole ring, furan ring, thiophene ring, oxazole ring, isoxazole ring,thiazole ring, isothiazole ring, furazan ring, and selenophene ring, andsilole ring that may have a substituent, and a fused heterocyclic ringgroup in which a monocyclic heterocyclic ring and an aromatichydrocarbon ring are arbitrarily combined and fused; examples of thearalkyl group include a benzyl group, a phenylethyl group, and aphenethyl group. R₅₈ and R₅₉ may be coupled with each other to form afive-membered heterocyclic ring or a six-membered heterocyclic ring.Herein, examples of the five-membered or six membered heterocyclic ringinclude a pyridine ring, a pyradine ring, a pyrimidine ring, apyridazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, afuran ring, a thiophene ring, an oxazole ring, an isoxazole ring, athiazole ring, an isothiazole ring, a furazan ring, a selenophene ring,and a silole ring. n₅ and n₆ each independently represent an integer of0 or more.

where X₄═Y₄ is represented by N═N or CR₆₇═N, R₆₇ is selected from thegroup consisting of a hydrogen atom, linear or branched alkyl, alkenyl,alkoxy, alkylthio, alkyl ester, and aryl groups each having 1 to 12carbon atoms. Herein, examples of the alkyl group include a methylgroup, an ethyl group, a propyl group, an isopropyl group, a butylgroup, an isobutyl group, an s-butyl group, and a t-butyl group;examples of the alkenyl group include a vinyl group and an allyl group;examples of the alkoxy group include a methoxy group, an ethoxy group,and a propoxy group; examples of the alkylthio group include amethylthio group and an ethylthio group; examples of the alkyl estergroup include a methyl ester group, an ethyl ester group, a propyl estergroup, and a butyl ester group; examples of the aryl group include aphenyl group and naphthyl group that may have a substituent. R₆₁ to R₆₆are each independently selected from the group consisting of a linear orbranched alkyl group, alkoxy group, aryl group, heterocyclic group,aralkyl group, and phenoxy group that have 1 to 12 carbon atoms and maybe substituted or unsubstituted, a cyano group, a nitro group, an estergroup, a carboxyl group, and a halogen atom. Examples of the alkyl groupinclude a methyl group, an ethyl group, a propyl group, an isopropylgroup, a butyl group, an isobutyl group, an s-butyl group, and a t-butylgroup; examples of the alkoxy group include a methoxy group, an ethoxygroup, and a propoxy group; examples of the ester group include a methylester group, an ethyl ester group, a propyl ester group, and a butylester group; examples of the aryl group include a phenyl group andnaphthyl group that may have a substituent; examples of the heterocyclicring group include a monocyclic heterocyclic ring group such as amonovalent pyridine ring, pyradine ring, pyrimidine ring, pyridazinering, pyrrole ring, imidazole ring, pyrazole ring, furan ring, thiophenering, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring,furazan ring, and selenophene ring, and silole ring that may have asubstituent, and a fused heterocyclic ring group in which a monocyclicheterocyclic ring and an aromatic hydrocarbon ring are arbitrarilycombined and fused; examples of the aralkyl group include a benzylgroup, a phenylethyl group, and a phenethyl group. R₆₅ and R₆₆ may becoupled with each other to form a five-membered heterocyclic ring or asix-membered heterocyclic ring. Examples of the five-membered or sixmembered heterocyclic ring include a pyridine ring, a pyradine ring, apyrimidine ring, a pyridazine ring, a pyrrole ring, an imidazole ring, apyrazole ring, a furan ring, a thiophene ring, an oxazole ring, anisoxazole ring, a thiazole ring, an isothiazole ring, a furazan ring, aselenophene ring, and a silole ring. n₇ and n₈ each independentlyrepresent an integer of 0 or more.

Of those structures, the B ring of the general formula (9) is preferablya structure represented by one of the following general formulae (27),(28), and (29) in consideration of, for example, an influence of theremaining of components that are to be eliminated with light onsemiconductor characteristics:

where R₅₄ to R₅₉ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom. Examples of the alkyl group include a methyl group, an ethylgroup, a propyl group, an isopropyl group, a butyl group, an isobutylgroup, an s-butyl group, and a t-butyl group; examples of the alkoxygroup include a methoxy group, an ethoxy group, and a propoxy group;examples of the ester group include a methyl ester group, an ethyl estergroup, a propyl ester group, and a butyl ester group; examples of thearyl group include a phenyl group and naphthyl group that may have asubstituent; examples of the heterocyclic ring group include amonocyclic heterocyclic ring group such as a monovalent pyridine ring,pyradine ring, pyrimidine ring, pyridazine ring, pyrrole ring, imidazolering, pyrazole ring, furan ring, thiophene ring, oxazole ring, isoxazolering, thiazole ring, isothiazole ring, furazan ring, and selenophenering, and silole ring that may have a substituent, and fusedheterocyclic ring group in which a monocyclic heterocyclic ring and anaromatic hydrocarbon ring are arbitrarily combined and fused; examplesof the aralkyl group include a benzyl group, a phenylethyl group, and aphenethyl group. R₅₈ and R₅₉ may be coupled with each other to form afive-membered heterocyclic ring or a six-membered heterocyclic ring.Examples of the five-membered or six membered heterocyclic ring includea pyridine ring, a pyradine ring, a pyrimidine ring, a pyridazine ring,a pyrrole ring, an imidazole ring, a pyrazole ring, a furan ring, athiophene ring, an oxazole ring, an isoxazole ring, a thiazole ring, anisothiazole ring, a furazan ring, a selenophene ring, and a silole ring.n₅ and n₆ each independently represent an integer of 0 or more.

where R₇₁ to R₇₆ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom. Examples of the alkyl group include a methyl group, an ethylgroup, a propyl group, an isopropyl group, a butyl group, an isobutylgroup, an s-butyl group, and a t-butyl group; examples of the alkoxygroup include a methoxy group, an ethoxy group, and a propoxy group;examples of the ester group include a methyl ester group, an ethyl estergroup, a propyl ester group, and a butyl ester group; examples of thearyl group include a phenyl group and naphthyl group that may have asubstituent; examples of the heterocyclic ring group include amonocyclic heterocyclic ring group such as a monovalent pyridine ring,pyradine ring, pyrimidine ring, pyridazine ring, pyrrole ring, imidazolering, pyrazole ring, furan ring, thiophene ring, oxazole ring, isoxazolering, thiazole ring, isothiazole ring, furazan ring, and selenophenering, and silole ring that may have a substituent, and a fusedheterocyclic ring group in which a monocyclic heterocyclic ring and anaromatic hydrocarbon ring are arbitrarily combined and fused; examplesof the aralkyl group include a benzyl group, a phenylethyl group, and aphenethyl group. R₇₅ and R₇₆ may be coupled with each other to form afive-membered heterocyclic ring or a six-membered heterocyclic ring.Examples of the five-membered or six membered heterocyclic ring includea pyridine ring, a pyradine ring, a pyrimidine ring, a pyridazine ring,a pyrrole ring, an imidazole ring, a pyrazole ring, a furan ring, athiophene ring, an oxazole ring, an isoxazole ring, a thiazole ring, anisothiazole ring, a furazan ring, a selenophene ring, and a silole ring.n₉ and n₁₀ each independently represent an integer of 0 or more;

where R₇₇ to R₈₂ are each independently selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom. Examples of the alkyl group include a methyl group, an ethylgroup, a propyl group, an isopropyl group, a butyl group, an isobutylgroup, an s-butyl group, and a t-butyl group; examples of the alkoxygroup include a methoxy group, an ethoxy group, and a propoxy group;examples of the ester group include a methyl ester group, an ethyl estergroup, a propyl ester group, and a butyl ester group; examples of thearyl group include a phenyl group and naphthyl group that may have asubstituent; examples of the heterocyclic ring group include amonocyclic heterocyclic ring such as a monovalent pyridine group,pyradine group, pyrimidine group, pyridazine group, pyrrole group,imidazole group, pyrazole group, furan group, thiophene group, oxazolegroup, isoxazole group, thiazole group, isothiazole group, furazangroup, and selenophene group, and silole group that may have asubstituent, and a fused heterocyclic ring group in which a monocyclicheterocyclic ring having a single ring and an aromatic hydrocarbon ringare arbitrarily combined and fused; examples of the aralkyl groupinclude a benzyl group, a phenylethyl group, and a phenethyl group. R₈₁and R₈₂ may be coupled with each other to form a five-memberedheterocyclic ring or a six-membered heterocyclic ring. Examples of thefive-membered or six membered heterocyclic ring include a pyridine ring,a pyradine ring, a pyrimidine ring, a pyridazine ring, a pyrrole ring,an imidazole ring, a pyrazole ring, a furan ring, a thiophene ring, anoxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, afurazan ring, a selenophene ring, and a silole ring. n₁₁ and n₁₂ eachindependently represent an integer of 0 or more.

Of those structures, a more preferred example includes a compound inwhich all of Z₁ to Z₄ of the general formula (9) are represented by CH,and the B ring of the formula is represented by the general formula(27), or all of Z₁ to Z₄ of the general formula (9) are represented by anitrogen atom, and the B ring of the formula is represented by thegeneral formula (27).

A method of synthesizing those compounds is not limited, but thecompounds can be synthesized by, for example, the following synthesismethod.

A porphyrin ring in a compound in which all of Z₁ to Z₄ of the generalformula (9) are represented by CH, and the B ring of the formula isrepresented by the general formula (27) can be formed by, for example, amethod shown in reaction formulae (4) to (7), whereby a porphyrincompound having 1 to 4 B rings can be synthesized.

In each of the reaction formulae (4) to (7), Compound (4) having 1 to 3B rings can be synthesized by: condensing Compound (1) and Compound (2)in the presence of an acid catalyst such as trichloroacetic acid;subjecting the condensate to an oxidation reaction to produce Compound(3); forming a diol body by deprotection with an acid such ashydrochloric acid; and subjecting the diol body to an oxidation reactionsuch as Swern oxidation.

As shown in the reaction formula (8), Compound (3) can be obtained by:reducing Compound (1) to produce Compound (2); and turning Compound (2)into a tetrameric ring in the presence of an acid catalyst. Compound (4)having 4 B rings can be synthesized by deprotection and oxidation ofCompound (3) thus obtained.

In addition, a substituent can be introduced to a meso-position byallowing a compound in which a hydrogen atom is present at α-position ofpyrrole, dipyrromethane, or tripyrane at the time of a cyclizationreaction to react with various aldehydes in the presence of an acidcatalyst.

In addition, when a metal is coordinated at the center of the porphyrinring, any method may be used, but a method involving causing a metalacetate or the like to act on a non-metal body is preferable.

Pyrroles having various substituents at the β-positions can be used asconstitutional units of such porphyrin compound as described above. Thepyrroles having various substituents at the β-positions can besynthesized by employing a method typified by a Barton-Zard method or aKnorr method. In addition, a raw material for the porphyrin compoundsuch as dipyrromethane or tripyrane can be synthesized by appropriatelycombining those pyrroles.

In addition, while there is no specific limitation concerning methods ofsynthesizing pyrroles each having a group that can be converted into theB ring, an acetonide-protected body is suitably used as a group that canbe converted into the B ring, and each pyrrole can be synthesized by,for example, such method as shown in reaction formulae (9) to (11).

As shown in the reaction formula (9), pyrrole can be synthesized by aDiels-Alder reaction of cyclohexadiene with bissulfonylethylene, and,subsequently, a Barton-Zard method. In addition, a substituent atα-position can be converted as shown in Route 1 for decarboxylation orRoute 2 for reduction.

As shown in the reaction formula (10), pyrrole can be synthesized by aDiels-Alder reaction of cyclohexadiene with benzyne, and, subsequently,addition of PhSCl, an oxidation reaction, and a Barton-Zard method. Inaddition, a substituent at α-position can be converted as shown in Route1 or Route 2.

As shown in the reaction formula (11), Compound (4) is synthesized by aDiels-Alder reaction of cyclohexadiene with naphthoquinone, followed bya reaction of the resultant with a base to produce Compound (3), areaction of the compound with hydrazine, and treatment of the resultantwith a base for aromatization. Thereafter, pyrrole can be synthesized byaddition of PhSCl, oxidation, and, subsequently, a Barton-Zard method.After that, a substituent at α-position can be converted as shown inRoute 1 or Route 2.

In addition, an azaporphyrin compound in which all of Z₁ to Z₄ of thegeneral formula (9) are represented by a nitrogen atom, and the B ringof the formula is represented by the general formula (27) can besynthesized by, for example, such method as shown in a reaction formula(12). The method involves: turning Dicyano Compound 1 into a tetramericring; and deprotecting and oxidizing the resultant to synthesize thecompound.

There is no specific limitation concerning a method of synthesizingDicyano Compound 1 in the reaction formula (12) as a raw material forthe azaporphyrin compound, but an acetonide-protected body is suitablyused as a group that can be converted into the B ring, and the compoundcan be synthesized by, for example, such method as shown in a reactionformula (13) or (14).

A nitrile compound can be synthesized by a Diels-Alder reaction ofcyclohexadiene protected by an acetonide with dicyanoacetylene.

Compound 5 can be synthesized by a Diels-Alder reaction ofAcetonide-protected Cyclohexadiene 1 with Ethylene Compound 2,reduction, and chlorination. After that, Dicyano Compound 8 can besynthesized by synthesis of Exomethylene 6 through dehydrochlorination,a Diels-Alder reaction of Exomethylene 6 with dicyanoacetylene, andaromatization.

The above-exemplified synthesis methods are only a few examples.Specific examples of the structure represented by the general formula(27) suitably used as the B ring are listed in Table 3. It should benoted that the substituent X in the skeletons listed in the table isselected from a hydrogen atom, a halogen atom, a cyano group, a nitrogroup, a linear or branched alkyl group having 1 to 12 carbon atoms, aphenyl group, and an ester group, and X's may be identical to ordifferent from each other.

TABLE 3 B ring No. B Ring 1

2

3

4

5

6

7

8

9

Of those exemplified compounds, a structure represented by a generalformula (21) is particularly preferable.

where R₈₃ to R₈₈ are each independently selected from the groupconsisting of a hydrogen atom, a hydroxyl group, a halogen atom, analkyl group, an alkoxy group, an alkylthio group, an ester group, anaryl group, a heterocyclic group, and an aralkyl group. Examples of thealkyl group include a methyl group, an ethyl group, a propyl group, anisopropyl group, a butyl group, an isobutyl group, an s-butyl group, anda t-butyl group; examples of the alkenyl group include a vinyl group andan allyl group; examples of the alkoxy group include a methoxy group, anethoxy group, and a propoxy group; examples of the alkylthio groupinclude a methylthio group and an ethylthio group; examples of the alkylester group include a methyl ester group, an ethyl ester group, a propylester group, and a butyl ester group; examples of the aryl group includea phenyl group and naphthyl group that may have a substituent; R₅₄ toR₅₉ each are selected independently from a hydrogen atom, an alkylgroup, an alkoxy group, an aryl group, a heterocyclic group, an aralkylgroup, a phenoxy group, a cyano group, a nitro group, an ester group, acarboxyl group, and a halogen atom; examples of the alkyl group includea methyl group, an ethyl group, a propyl group, an isopropyl group, abutyl group, an isobutyl group, an s-butyl group, and a t-butyl group;examples of the alkoxy group include a methoxy group, an ethoxy group,and a propoxy group; examples of the ester group include a methyl estergroup, an ethyl ester group, a propyl ester group, and a butyl estergroup; examples of the aryl group include a phenyl group and naphthylgroup that may have a substituent; examples of the heterocyclic ringgroup include a monocyclic heterocyclic ring such as a monovalentpyridine ring, pyradine ring, pyrimidine ring, pyridazine ring, pyrrolering, imidazole ring, pyrazole ring, furan ring, thiophene ring, oxazolering, isoxazole ring, thiazole ring, isothiazole ring, furazan ring,selenophene group ring, and silole ring that may have a substituent, anda fused heterocyclic ring group in which a monocyclic heterocyclic ringand an aromatic hydrocarbon ring are arbitrarily combined and fused;examples of the aralkyl group include a benzyl group, a phenylethylgroup, and a phenethyl group. M₄ represents two hydrogen atoms, a metalatom, or a metal oxide. Examples of the metal include copper, gold,silver, zinc, nickel, chromium, magnesium, and lithium. Examples of themetal oxide include TiO and VO. M4 represents particularly preferablytwo hydrogen atoms or a copper atom. Each pair of R₈₃ and R₈₄, R₈₅ andR₈₆, or R₈₇ and R₈₈ may be combined together to form a general formula(30).

Preferable examples of the above-mentioned organic semiconductorprecursor to be used in the present invention are shown below.

Unsubstituted structures are primarily shown in the examples, but theprecursor may have a substituent, or a metal may coordinate at thecenter of the precursor. Compounds shown here are merely examples, andthe compound of the present invention is by no means limited thereto.

Therefore, for example, the following general formula (32) can berewritten into a general formula (22).

Hereinafter, specific examples of the organic semiconductor precursorare shown.

It should be noted that such a compound as the present invention iseffective for solubilization of benzoporphyrin or phthalocyanine, and,furthermore, only the portion of the compound irradiated with light canbe transformed into a photosensitizing dye, so the compound issufficiently expected to have, for example, an effect of reducing damageto normal cells. Therefore, in addition to the fact that the compoundcan be used in a method of producing an organic semiconductor device,the compound may be developed into a photosensitizing dye for PDT. Inaddition, such a pigment as phthalocyanine or porphyrin can be producedby irradiation with light, so the compound has potential for applicationin the field of printing where light is utilized and for forming a p-njunction at the molecular level by irradiation with light, and may beapplied to, for example, an organic thin-film solar cell having highsensitivity and a large area. The application of such organicsemiconductor precursor onto a base body results in the formation of alayer composed of the organic semiconductor precursor. A method offorming the layer composed of the organic semiconductor precursor ispreferably a method in which the organic semiconductor precursor isdissolved in an organic solvent and applied onto the base body to formthe layer. An organic solvent to be used for dissolving the organicsemiconductor precursor is not particularly limited as long as anorganic semiconductor material neither reacts with the solvent norprecipitates. In addition, two or more types of organic solvents may beused as a mixture. In this case, taking into account the surfacesmoothness and thickness uniformity of a coating film, it is desirableto select the solvent.

Examples of the solvent include acetone, methylethyl ketone,methylisobutyl ketone, cyclohexanone, hexane, heptane, cyclohexane,tetrahydrofuran, dioxane, diethyl ether, isopropyl ether, dibutyl ether,toluene, xylene, 1,2-dimethoxyethane, chloroform, methylene chloride,dichloroethane, 1,2-dichloroethylene, dimethylsulfoxide,N-methylpyrrolidone, chlorobenzene, dichlorobenzene, andtrichlorobenzene. Each of them may be used alone as a solvent, or amixture of two or more of them may be used as a solvent. Theconcentration of a solution comprised of the organic semiconductorprecursor and the solvent, which is arbitrarily adjusted depending on adesired thickness, is preferably 0.01 wt % or more and 5 wt % or less.

A method of applying the solution comprised of the organic semiconductorprecursor and the solvent onto the base body is not particularlylimited. Examples of the application method include the conventionalcoating methods such as a spin coating method, a cast method, a spraycoating method, a doctor blade method, a die coating method, a dippingmethod, a printing method, an inkjet method, and a dropping method. Inaddition, examples of the printing method include screen printing,offset printing, gravure printing, flexographic printing, andmicrocontact printing. Of those application methods, the spin coatingmethod, the dipping method, the spray coating method, and the inkjetmethod are preferable because the application amount can be controlledso that a film having a desired thickness is formed. Further, to preventthe intrusion of dust and the like in a coating film as much aspossible, it is desirable to filter the solution in advance by means ofa membrane filter. This is because the intrusion of insoluble matter ordust from the outside may obstruct uniform orientation, therebyincreasing an OFF current and reduction an ON/OFF ratio. In addition,the coating film of the organic semiconductor precursor can be subjectedto preliminary drying.

An organic semiconductor film obtained through the foregoing operationshas a thickness of preferably 10 nm or more and 500 nm or less, or morepreferably 20 nm or more and 200 nm or less. The thickness can bemeasured with, for example, a surface roughness meter or a leveldifference meter.

Next, in step (ii), the formed layer composed of the organicsemiconductor precursor is irradiated with light.

The irradiation of the layer composed of the organic semiconductorprecursor with light bring about such reverse Diels-Alder reaction asshown in the reaction formulae (1) to (3), whereby a layer composed ofan organic semiconductor is formed. The wavelength of light with whichthe layer composed of the organic semiconductor precursor is irradiated,is only required to fall within an absorption wavelength region of theorganic semiconductor precursor, but preferably falls within awavelength region of 190 nm or more and 500 nm or less. This is becausea wavelength shorter than 190 nm may cause damage to the peripheral partof the layer or a side reaction, and a wavelength in excess of 500 nmmay cause damage to the resultant organic semiconductor. A light sourceis selected from, for example, a tungsten lamp, a halogen lamp, a metalhalide lamp, a sodium lamp, a xenon lamp, a high-pressure mercury lamp,a low-pressure mercury lamp, and various laser light beams. A method ofirradiating the layer with light is not particularly limited as long asthe organic semiconductor precursor is converted into the organicsemiconductor, but a method of directly irradiating the organicsemiconductor precursor with light is desirable in order that aphotoreaction may be more effectively performed. It should be notedthat, when heat generated by irradiation with light is applied to theorganic semiconductor precursor, the heat is preferably cut off with aheat absorbing filter or the like. In addition, the organicsemiconductor can be patterned by irradiating the layer with lightthrough a mask. It is more preferable that light and heat besimultaneously applied to the layer composed of the organicsemiconductor precursor in order that an excellent crystallized film ofthe organic semiconductor may be obtained. This is because, when lightenergy and heat energy are simultaneously applied to the layer, theorganic semiconductor precursor is converted into the organicsemiconductor with light, and gaps in crystal grains produced by anelimination reaction are filled with heat energy. As a result, the layercomposed of the organic semiconductor can be led to such a more stablecrystalline state that oxygen or moisture hardly infiltrates into thelayer.

In that case, heat is applied by externally heating the base body. Anymethod may be employed as a heating method, but a method is preferablein which the base body is heated on a hot plate, or in an oven withinternal air circulation or a vacuum oven. Of those, the method in whichthe base body is heated on a hot plate is more preferable. The optimumtemperature at which the base body is heated varies depending on thetype of organic semiconductor precursor, but the base body is preferablyheated in the temperature region of 50° C. or higher and 180° C. orlower in consideration of, for example, an influence on the peripheralpart of the layer.

When light and heat are simultaneously applied to the layer, the timeperiod for which light and heat are simultaneously applied to the layervaries depending on, for example, the thickness and material of thelayer to a large extent, so the time period cannot be uniquelydetermined. In general, however, it becomes difficult for light topermeate into a deep portion of the crystallized film of the organicsemiconductor as the film grows, so the time period for which lightenergy and heat energy are simultaneously applied to the layer ispreferably 1 second or longer and 30 minutes or shorter. In such amanner, light can be effectively utilized in converting the organicsemiconductor precursor into the organic semiconductor. The time periodfor which light energy and heat energy are simultaneously applied to thelayer is more preferably 1 minute or longer and 15 minutes or shorter.In addition, in order that a more stable crystallized film can beobtained, only heat energy may be further applied after simultaneouslyapplying light energy and heat energy.

The layer composed of the organic semiconductor obtained through thoseoperations has a thickness of preferably 10 nm or more and 500 nm orless, or more preferably 20 nm or more and 200 nm or less. The thicknesscan be measured with, for example, a surface roughness meter or a leveldifference meter.

In the present invention, the base body is an object on which the layercomposed of the organic semiconductor precursor is to be formed.

The base body may be comprised of a single layer, or multiple layers.

When the base body is comprised of multiple layers, the outermost layeris preferably a crystallization promoting layer. When the outermostlayer is a crystallization promoting layer, a ground on which thecrystallization promoting layer is to be formed (in the case of a fieldeffect transistor, the ground is generally a structure comprised of asupport layer, a gate electrode, and a gate insulating layer; providedthat the gate insulating layer can be omitted in some cases, thestructure may be comprised only of the support layer depending on theorder in which the layers are superimposed, and other layers may beformed) is referred to as a base material.

According to detailed investigation conducted by the inventors of thepresent invention, the simultaneous application of light energy and heatenergy to the layer composed of the organic semiconductor precursor onthe crystallization promoting layer to transform the layer formed of theorganic semiconductor precursor into the layer formed of the organicsemiconductor may be important for bringing out the crystallizationpromoting function to the maximum. In general, when the organicsemiconductor precursor is subjected to an elimination reaction byapplying light energy and heat energy to the precursor to produce theorganic semiconductor, the production of a gap between crystal grainscomposed of the resultant compound is observed. On the other hand, whensuch reaction is performed on the crystallization promoting layer, thegap between the crystal grains of the layer composed of the organicsemiconductor is filled, whereby uniform crystals are formed over theentire substrate.

This is probably because the crystallization promoting layer has afunction of stabilizing the crystal grains of the layer composed of theorganic semiconductor (the stabilization may involve the movement orrotation of the grains) and promoting the junction between the crystalgrains. Therefore, the crystallization promoting layer is a layer forstabilizing crystal grains (the stabilization may involve the movementor rotation of the grains) and/or promoting junction between the crystalgrains.

The inventors of the present invention consider that the crystallizationpromoting layer functions by virtue of an improvement in crystallinityof the layer composed of the organic semiconductor by such action of thecrystallization promoting layer. The occurrence of the junction betweenthe crystal grains is considered to be particularly preferable.

Such crystallization promoting layer is preferably a layer containing apolysiloxane compound.

Within the scope of investigation conducted by the inventors of thepresent invention, the polysiloxane compound may have an action ofpromoting the crystallization of the organic semiconductor.

Further, the inventors of the present invention have found that a methodinvolving simultaneously applying light energy and heat energy to thelayer formed of the organic semiconductor precursor after theapplication (lamination) of the layer composed of the organicsemiconductor precursor onto the surface of the layer containing thepolysiloxane compound is effective for the formation of a layer composedof the organic semiconductor with high quality. Hereinafter, the layercontaining the polysiloxane compound may also be referred to simply as“polysiloxane compound layer”. According to such a method, organicsemiconductor crystals can be formed which, at the interface between thelayer containing the polysiloxane compound and the layer formed of theorganic semiconductor, is continuously uniform and less in defect, andhardly deteriorates owing to external stimuli such as oxygen or water.Accordingly, it is considered that organic semiconductor devices can beproduced in which the variation in characteristics between the devicesare small and high in durability. While such a method may be useful forany organic semiconductor device, it is considered to be particularlyuseful for the production of an organic field effect transistor which isan example of the organic semiconductor devices.

In the present invention, the term “polysiloxane compound” refers to apolymer having a siloxane structure (—Si—O—) and an organic silanestructure, and the term “layer composed of the polysiloxane compound”refers to a layer composed of a polymer having a siloxane structure(—Si—O—) and an organic silane structure. Therefore, the polysiloxanecompound may be a copolymer with any other organic or inorganic polymeras long as the compound has the above structures. In the case of acopolymer with any other polymer, the siloxane structure or the organicsilane structure may be present in its main chain or in its side chaindue to graft polymerization or the like. It should be noted that theorganic silane structure is a structure obtained by directly bonding Siand C.

Possible examples of the polysiloxane compound include compounds havingvarious structures such as a linear structure and a cyclic structure.

The polysiloxane compound more preferably has a highly crosslinked orbranched structure. The term “highly crosslinked or branched structure”as used herein comprehends network, ladder-like, cage-like, star-like,and dendritic structures. In addition, the crosslinked or branchedstructure does not necessarily need to be formed through the siloxanestructure. The structure may contain a structure obtained bycrosslinking organic groups such as a vinyl group, an acryloyl group, anepoxy group, and a cinnamoyl group, or a structure branched through anorganic group which is trifunctional or more.

Examples of the polysiloxane compound include compounds each having astructure represented by the following general formula (6). The mainchain of such structure is a siloxane unit, and the side chains (R₅ toR₈) of the structure are each a substituent having an organic group suchas a hydrogen atom or a carbon atom.

In the formula, R₅ to R₈ each represent a substituted or unsubstitutedalkyl or alkenyl group having 1 to 8 carbon atoms, a substituted orunsubstituted phenyl group, or a siloxane unit, and R₅ to R₈ may beidentical to or different from one another.

Examples of the substituted alkyl group include an alkyl group in whicha hydrogen atom is substituted by a halogen atom, a hydroxyl group, acyano group, a phenyl group, a nitro group, a mercapto group, or aglycidyl group. In addition, a methyl group and a methylene group may besubstituted by an amino group. Further, examples of the substitutedphenyl group include a phenyl group in which a hydrogen atom is replacedby a halogen atom, a hydroxyl group, a cyano group, a nitro group, amercapto group, or a glycidyl group. Of course, the substituent is notlimited to them. It should be noted that those examples hold true forall of R's and R_(n)'s (n represents a natural number) in siloxanecompounds described below except for a logically improbable exception.

The substituents R₅ to R₈ may each independently be one of such siloxaneunits as shown below:

where R's are each independently a substituted or unsubstituted alkylgroup having 1 to 8 carbon atoms, a substituted or unsubstituted phenylgroup, or any one of the siloxane units shown above, and the respectiveR's may be the same functional group, or may be functional groupsdifferent from each other.

The shape of polysiloxane may include, for example, linear, cyclic,network, ladder-like, or cage-like structures depending on the types ofsubstituents in the general formula (6), and polysiloxane to be used inthe present invention may take any one of these structures.

Other examples of the polysiloxane compound to be used in the presentinvention include compounds each having such a structure as representedby the following general formula (8).

In the formula, R₁₃ to R₁₆ each represent a substituted or unsubstitutedalkyl or alkenyl group having 1 to 8 carbon atoms, or a substituted orunsubstituted phenyl group, R₁₃ to R₁₆ may be identical to or differentfrom one another, r and p each independently represent an integer of 0or more, and the sum of r and p represents an integer of 1 or more.

The polysiloxane compound to be used in the present inventionparticularly preferably has at least such a specific silsesquioxaneskeleton as represented by the following general formula (7).

In the formula, R₉ to R₁₂ each represent a substituted or unsubstitutedalkyl or alkenyl group having 1 to 8 carbon atoms, or a substituted orunsubstituted phenyl group, R₉ to R₁₂ may be identical to or differentfrom one another, m and n each independently represent an integer of 0or more, and the sum of m and n represents an integer of 1 or more. Thecompound may be a random copolymer or a block copolymer. Extremelyspecific examples of R₉ to R₁₂ include: an unsubstituted alkyl groupsuch as a methyl group or an ethyl group; an unsubstituted phenyl group;and a substituted phenyl group such as a dimethylphenyl group or anaphthyl group. In addition, the substituents R₉ to R₁₂ may containvarious atoms such as an oxygen atom, a nitrogen atom, and a metal atomas well as a carbon atom and a hydrogen atom.

The silsesquioxane skeleton in the present invention will be described.The general formula (7) shows a structure in which m repeatingsilsesquioxane units each having the substituents R₉ and R₁₀(hereinafter referred to as “first units”) and n repeatingsilsesquioxane units each having the substituents R₁₁ and R₁₂(hereinafter referred to as “second units”) are connected to each other.m and n each independently represent an integer of 0 or more, and m+n isan integer of 1 or more. However, the foregoing does not mean that therepetition of the first units and the repetition of the second units areseparated from each other. Both the units may be connected to each otherin a separate manner or in a randomly intermingled manner.

In addition, a siloxane compound having both a structure represented bythe general formula (7) and a structure represented by the generalformula (8) can also be used as a polysiloxane compound in the presentinvention.

As for a method of forming the crystallization promoting layer in thepresent invention composed mainly of a compound having such specificsilsesquioxane skeleton as represented by the general formula (7) on thebase material, the following method is exemplified. That is, a solutioncontaining polyorganosilsesquioxane compounds represented by at leastone of the following general formulae (10) and (11) is applied onto thebase material and is heated and dried, whereby the base body can beobtained.

In this case, heating is carried out at a temperature of preferably 140°C. or higher and 300° C. or lower, or more preferably 150° C. or higherand 230° C. or lower. When heating is carried out at lower than 140° C.,the hydrolysis reaction of the solution may be insufficient.

In the formula, R₉ and R₁₀ each represent a substituted or unsubstitutedalkyl or alkenyl group having 1 to 8 carbon atoms, or a substituted orunsubstituted phenyl group, R₉ and R₁₀ may be the same functional group,R₂₆ to R₂₉ each independently represent an alkyl group having 1 to 4carbon atoms, or a hydrogen atom, and z represents an integer of 1 ormore.

In the formula, R₁, and R₁₂ each represent a substituted orunsubstituted alkyl or alkenyl group having 1 to 8 carbon atoms, or asubstituted or unsubstituted phenyl group, R₁₁ and R₁₂ may be the samefunctional group, R₃₀ to R₃₃ each independently represent an alkyl grouphaving 1 to 4 carbon atoms, or a hydrogen atom, and y represents aninteger of 1 or more.

A hydrolysis reaction is induced at the terminal of each compound bysuch heating and drying, whereby the silsesquioxane compounds as rawmaterials are connected to each other in ladder form so as to bedensified, provided that the temperature at which the raw materialcompounds are heated and dried is not so high that organic mattercompletely disappears, so the raw material compounds can be turned intonot a complete silica structure but a silsesquioxane skeleton in whichmost of substituents remain.

In addition, at the time of the drying step, a small amount of an acidsuch as formic acid may be added to the solution to be applied for thepurpose of aiding a reaction in which the silsesquioxane compounds asoligomers mutually crosslink.

The addition amount of the acid is not particularly limited. When formicacid is used as the acid, the acid is preferably added in an amount inthe range of 1 wt % to 30 wt % with respect to the solid content weightof the polyorganosilsesquioxane compounds in the solution to be appliedbecause crosslinking reaction is promoted. When the addition amount issmaller than 1 wt %, the effect of promoting crosslinking reaction maybe insufficient. In contrast, when the addition amount is larger than 30wt %, the properties of the film having been dried may be impaired.

In the process of the crosslinking reaction and the removal of thesolvent of the solution, a stabilizer that does not evaporate,volatilize, or burn off in the system is removed from the solutionsystem as much as possible.

Any one of arbitrary solvents including alcohols and esters can be usedas the solvent of the solution to be applied. The solvents are selectedin consideration of, for example, wettability for a substrate.

A method of applying a raw material solution for the crystallizationpromoting layer onto the base material is not particularly limited. Asthe application method, the conventional coating methods can beemployed, such as a spin coating method, a cast method, a spray coatingmethod, a doctor blade method, a die coating method, a dipping method, aprinting method, an inkjet method, and a dropping method. Examples ofthe printing method include screen printing, offset printing, gravureprinting, flexographic printing, and microcontact printing. Of thoseapplication methods, the spin coating method, the dipping method, thespray coating method, and the inkjet method are preferable because theapplication amount can be controlled so that a film having a desiredthickness is formed. In addition, it is important that dust and the likeare mixed into an application solution to the extent possible to retainthe insulation properties of the obtained film, so it is desirable thata raw material solution be filtrated with a membrane filter in advance.

The concentration of the solution is preferably adjusted so that thecrystallization promoting layer has a thickness of 10 nm or more. Theconcentration is more preferably adjusted so that the layer has athickness of 15 nm or more and 500 nm or less. This is because, when thethickness is less than 10 nm, it may become difficult to obtain auniform film.

Prior to the application of the raw material solution for thecrystallization promoting layer, the surface of the base material may bemodified by, for example, ultrasonic treatment with an alkali liquid orirradiation with UV for the purpose of improving wettability of thesurface of the base material.

The organic semiconductor precursor is applied onto the base body onwhich the crystallization promoting layer has been formed. Thus, thelayer composed of the organic semiconductor precursor is formed. In thiscase, it is desirable that the crystallization promoting layer and thelayer composed of the organic semiconductor precursor are superimposedin close contact with each other. The term “close contact” refers to astate that at least part of the crystallization promoting layer and atleast part of the layer composed of the organic semiconductor precursorare in contact with each other without the intervention of any otherlayer.

As described above, the layer composed of the organic semiconductorprecursor is formed on the crystallization promoting layer. After that,the simultaneous application of light and heat results in the conversionof a bicyclo skeleton into an aromatic ring (conversion of the precursorinto the organic semiconductor). Crystal growth due to the stacking oforganic semiconductor molecules occurs simultaneously with theconversion into the aromatic ring, whereby the crystallized film of theorganic semiconductor is formed. Thus, the layer composed of the organicsemiconductor is formed.

FIG. 1 shows the schematic sectional view of an organic field effecttransistor where the organic field effect transistor is obtained throughthe above steps. The field effect transistor shown in FIG. 1 is made upof a gate electrode 1, an insulating layer 2, an A layer(crystallization promoting layer) 3, a source electrode 4, a drainelectrode 5, and a B layer (layer composed of an organic semiconductor)6. Description is given here on the assumption that a base material iscomprised of the gate electrode 1 and the insulating layer 2, and a basebody is comprised of the gate electrode 1, the insulating layer 2, andthe A layer (crystallization promoting layer) 3.

The gate electrode 1, the source electrode 4, and the drain electrode 5are not particularly limited as long as they are made of conductivematerials. Examples of the materials include: platinum, gold, silver,nickel, chromium, copper, iron, tin, antimonial lead, tantalum, indium,aluminum, zinc, magnesium, and alloys of those metals; conductive metaloxides such as an indium-tin oxide; and inorganic and organicsemiconductors with increased conductivity through doping and the like,such as a silicon single crystal, polysilicon, amorphous silicon,germanium, graphite, polyacetylene, polyparaphenylene, polythiophene,polypyrrole, polyaniline, polythienylenevinylene, andpolyparaphenylenevinylene. Examples of a method of producing anelectrode include a sputtering method, an evaporation method, a printingmethod from a solution or a paste, an inkjet method, and a dippingmethod. In addition, an electrode material is preferably any of theabove materials that have low electrical resistance at a contact surfacewith the organic semiconductor layer.

The insulating layer 2 is not limited as long as the A layer 3 can beuniformly applied to the layer, but the insulating layer is preferablyone having a high dielectric constant and low conductivity. Examples ofa material for the insulating layer include: inorganic oxides andnitrides such as silicon oxide, silicon nitride, aluminum oxide,titanium oxide, and tantalum oxide; and polyacrylate, polymethacrylate,polyethylene terephthalate, polyimide, and polyether. Of the aboveinsulating materials, an insulating material having high surfacesmoothness is preferable. In addition, the A layer itself is excellentin insulating property, and hence, the A layer itself may be used as agate insulating layer by adjusting the thickness of the A layer to sucha thickness that the layer exerts the insulating property.

A field effect transistor structure in the present invention may be anyone of a top contact electrode type, a bottom contact electrode type,and a top gate electrode type. In addition, the structure is not limitedto a horizontal type structure, and may be a vertical type structure(structure in which one of a source electrode and a drain electrode ispresent on the surface of an organic semiconductor layer on the side ofa base material and the other is present on the surface of the organicsemiconductor layer on the side opposite to the base material).

The third embodiment of the present invention is a method of producingan organic semiconductor device having a layer composed of an organicsemiconductor, including: (I) forming a layer composed of an organicsemiconductor precursor on a base body; and (II) subjecting the organicsemiconductor precursor heating and irradiating with light; and (III)the layer composed of the organic semiconductor precursor contains, asthe organic semiconductor precursor, a compound having in its moleculeat least one of a structure represented by the following general formula(5).

The organic semiconductor precursor to be used in the present inventioncontains an acene compound containing in its molecule at least one SCOskeleton represented by the general formula (5) as a partial structure.Such acene compound has preferably a structure represented by a generalformula (13), or more preferably a pentacene precursor.

In the formula, A is a cyclic structure, and represents an SCO skeletonrepresented by the general formula (12), or a five- or six-memberedheterocyclic ring. Examples of the five- or six-membered heterocyclicring include a pyridine ring, a pyrazine ring, a pyrimidine ring, apyridazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, afuran ring, a thiophene ring, an oxazole ring, an isoxazole ring, athiazole ring, an isothiazole ring, a furazan ring, a selenophene ring,and a silole ring. R₃₇ and R₄₂ each independently represent a hydrogenatom, an alkyl group, an alkoxyl group, an ester group, or a phenylgroup. R₃₄ to R₃₆, R₃₈ to R₄₁, and R₄₃ each independently represent ahydrogen atom, an alkyl group, an alkoxyl group, an aryl group, aheterocyclic group, an aralkyl group, a phenoxy group, a cyano group, anitro group, an ester group, a carboxyl group, or a halogen atom. Theterm “aryl group” as used herein refers to a monovalent, monocyclic orpolycyclic aromatic hydrocarbon group, and examples of the polycyclicaromatic hydrocarbon include hydrocarbons each obtained by condensingtwo to fifteen aromatic hydrocarbon rings, such as naphthalene,anthracene, azulene, heptalene, biphenylene, indacene, acenaphthylene,phenanthrene, triphenylene, pyrene, chrysene, picene, perylene,pentaphene, rubicene, coronene, pyranthrene, and ovalene. Positions atwhich the two to fifteen rings are condensed are not limited to those ofthe examples, and the rings may be condensed at any positions. Inaddition, examples of the heterocyclic ring include monocyclicheterocyclic rings such as monovalent pyridine, pyrazine, pyrimidine,pyridazine, pyrrole, imidazole, pyrazole, furan, thiophene, oxazole,isoxazole, thiazole, isothiazole, furazan, selenophene, and silolerings, and condensed heterocyclic groups each obtained by condensing anarbitrary combination of a monocyclic heterocyclic ring and an aromatichydrocarbon ring. The aryl group or the heterocyclic group may have asubstituent(s), and may be substituted by the substituent(s) at anyposition(s) as long as the group can be substituted by thesubstituent(s) at the position(s). Further, aryl groups, heterocyclicgroups, or an aryl group and a heterocyclic group may be combined witheach other to form an oligomer. R₃₄ to R₃₆, R₃₈ to R₄₁, and R₄₃ may beidentical to or different from one another. Each pair of R₃₄ and R₃₅,and R₃₉ and R₄₀ may be combined together to form an SCO skeleton, or afive- or six-membered heterocyclic ring. Here, examples of the five- orsix-membered heterocyclic ring include a pyridine ring, a pyrazine ring,a pyrimidine ring, a pyridazine ring, a pyrrole ring, an imidazole ring,a pyrazole ring, a furan ring, a thiophene ring, an oxazole ring, anisoxazole ring, a thiazole ring, an isothiazole ring, a furazan ring, aselenophene ring, and a silole ring. The sum of n₁ to n₄ represents aninteger of 1 or more. Of those, a structure to be converted into anacene-type compound with light, a structure to be converted into anoligomer obtained by coupling two to six identical or differentacene-type compounds as described above with light, or a structure to beconverted into a structure obtained by coupling the acene-type compoundwith a heterocyclic ring with light is more preferable. The term“acene-type compound” refers to a compound obtained by linearlycondensing three or more rings selected from aromatic hydrocarbon ringsand heterocyclic rings, such as anthracene, tetracene, pentacene,acridine, and thianthrene.

Examples of a preferable compound as the organic semiconductor precursorto be used in the present invention are shown below. It should be notedthat only a few examples are shown herein, and the compound of thepresent invention is not limited to them.

Any one of those organic semiconductor precursors is applied to the basebody in step (I), whereby the layer composed of the organicsemiconductor precursor is formed. A method of forming the layercomposed of the organic semiconductor precursor is preferably a methodin which the organic semiconductor precursor is dissolved in an organicsolvent and applied. An organic solvent to be used for dissolving theorganic semiconductor precursor is not particularly limited as long asan organic semiconductor material neither reacts with the solvent norprecipitates. Examples of the solvent include acetone, methylethylketone, methylisobutyl ketone, cyclohexanone, hexane, heptane,cyclohexane, tetrahydrofuran, dioxane, diethyl ether, isopropyl ether,dibutyl ether, toluene, xylene, 1,2-dimethoxyethane, chloroform,methylene chloride, dichloroethane, 1,2-dichloroethylene,dimethylsulfoxide, N-methylpyrrolidone, chlorobenzene, dichlorobenzene,and trichlorobenzene. The concentration of the solution is arbitrarilyadjusted depending on a desired thickness, and is preferably 0.01 wt %or more and 5 wt % or less. Taking into account the surface smoothnessand thickness uniformity of a coating film, a solvent is desirablyselected. In addition, two or more kinds of organic solvents may be usedas a mixture, and a polar solvent is particularly preferably mixed inthe mixture. This is because the mixing of the polar solvent is expectedto alleviate orientation resulting from the dipole of the SCO skeletonto lead the skeleton to a better orientation state, whereby thesemiconductor characteristic of the precursor improves, though thereason for the expectation is unclear. Examples of the polar solvent tobe mixed include nitrite-, ester-, alcohol-, and cyclic ether-typesolvents such as acetonitrile, ethyl acetate, acetone, methyl ethylketone, acetylacetone, tetrahydrofuran, dioxane, methanol, ethanol,n-propanol, isopropanol, n-butanol, and N-methylpyrrolidone. Of those,an alcohol-type solvent such as methanol, ethanol, 1-propanol,isopropanol, or n-butanol is particularly preferably mixed. The ratio atwhich the polar solvent is mixed, which is not particularly limited aslong as the organic semiconductor precursor neither reacts with thesolvent nor precipitates, is preferably such that the molar ratio of theorganic semiconductor precursor and the polar solvent (polarsolvent/organic semiconductor precursor) is 2 or more and 30 or less.

A method of forming layer composed of the organic semiconductorprecursor is not particularly limited. The formation method is performedby means of any one of the conventional coating methods such as a spincoating method, a cast method, a spray coating method, a doctor blademethod, a die coating method, a dipping method, a printing method, aninkjet method, and a dropping method. Examples of the printing methodinclude screen printing, offset printing, gravure printing, flexographicprinting, and microcontact printing. Of those application methods, thespin coating method, the dipping method, the spray coating method, andthe inkjet method are preferable because the application amount can becontrolled so that a film having a desired thickness is formed. Toprevent the intrusion of dust and the like in a coating film as much aspossible, it is desirable to filter the solution in advance by means ofa membrane filter. This is because the intrusion of insoluble matter ordust from the outside may obstruct uniform orientation, therebyincreasing an OFF current and reducing an ON/OFF ratio. In addition, thecoating film of the organic semiconductor precursor can be subjected topreliminary drying.

The layer formed of the organic semiconductor precursor thus formed isheated or irradiated with light in step (II), whereby such reverseDiels-Alder reaction as shown in the reaction formula (3) is broughtabout, and the layer composed of the organic semiconductor is formed.When the layer formed of the organic semiconductor is formed by heating,heat to be applied to the layer composed of the organic semiconductorprecursor, which is only required to have such a temperature that theprecursor is converted into the organic semiconductor, is preferablyheat at 100° C. or higher and 250° C. or lower. In addition, when thelayer composed of the organic semiconductor is formed by irradiationwith light, the wavelength of light with which the layer composed of theorganic semiconductor precursor is irradiated, is only required to fallwithin an absorption wavelength region of the organic semiconductorprecursor, and falls within a wavelength region of preferably 190 nm ormore and 350 nm or less, or more preferably 220 nm or more and 280 nm orless. When the wavelength falls within the above region, the precursorcan be efficiently converted into the organic semiconductor. A lightsource is selected from, for example, a tungsten lamp, a halogen lamp, ametal halide lamp, a sodium lamp, a xenon lamp, a high-pressure mercurylamp, a low-pressure mercury lamp, and various laser light beams. Amethod of irradiating the layer with light is not particularly limitedas long as the organic semiconductor precursor is changed to the organicsemiconductor, but a method of directly irradiating the organicsemiconductor precursor with light is desirable in order that aphotoreaction may be more effectively performed. When heat generated bythe irradiation with light is applied to the organic semiconductorprecursor, the heat is preferably cut off with a heat absorbing filteror the like. In addition, the organic semiconductor can be patterned byirradiating the layer with light through a mask. It is more preferablethat light and heat be simultaneously applied to the layer composed ofthe organic semiconductor precursor in order that an excellentcrystallized film of the organic semiconductor may be obtained. In thiscase, heat is applied by heating the base body from the outside of thebody. Any method may be employed as a heating method, but a preferablemethod is a method involving heating the base body on a hot plate, or inan oven with hot air circulation or a vacuum oven. Of those, in thepresent invention, a method involving heating the base body on a hotplate is more preferable. While the optimum temperature at which thebase body is heated varies depending on the type of organicsemiconductor precursor, the base body is preferably heated in thetemperature region of 50° C. or higher and 180° C. or lower inconsideration of, for example, an influence on the peripheral part ofthe layer.

As describe above, the concept of the term “or” includes “and”, and theheat and irradiation with light may be performed simultaneously. Whenlight and heat are simultaneously applied to the layer, the time periodfor which light and heat are simultaneously applied to the layer variesdepending on, for example, the thickness and material of the layer to alarge extent, so the time period cannot be uniquely determined. Ingeneral, however, it becomes difficult for light to permeate into a deepportion of the crystallized film of the organic semiconductor as thefilm grows, so the time period for which light energy and heat energyare simultaneously applied to the layer is preferably 1 second or longerand 30 minutes or shorter. In such a manner, light can be effectivelyutilized in converting the organic semiconductor precursor into theorganic semiconductor. The time period for which light energy and heatenergy are simultaneously applied to the layer is more preferably 1minute or longer and 15 minutes or shorter. In addition, in order toobtain a more stable crystallized film, only heat energy may be furtherapplied after simultaneously applying light energy and heat energy.

The layer formed of the organic semiconductor obtained through thoseoperations has a thickness of preferably 10 nm or more and 500 nm orless, or more preferably 20 nm or more and 200 nm or less. The thicknesscan be measured with, for example, a surface roughness meter or a leveldifference meter.

FIG. 2 shows the schematic sectional view of an organic field effecttransistor when the organic field effect transistor is obtained throughthe above steps. The field effect transistor shown in FIG. 2 is made upof a gate electrode 7, an insulating layer 8, a layer 9 composed of anorganic semiconductor, a source electrode 10, and a drain electrode 11.Description is given here on the assumption that a base body iscomprised of the gate electrode 7 and the insulating layer 8.

The gate electrode 7, the source electrode 10, and the drain electrode11 are not particularly limited as long as they are made of conductivematerials. Examples of the materials include: platinum, gold, silver,nickel, chromium, copper, iron, tin, antimonial lead, tantalum, indium,aluminum, zinc, magnesium, and alloys of those metals; conductive metaloxides such as an indium-tin oxide; and inorganic and organicsemiconductors with increased conductivity through doping and the like,such as a silicon single crystal, polysilicon, amorphous silicon,germanium, graphite, polyacetylene, polyparaphenylene, polythiophene,polypyrrole, polyaniline, polythienylenevinylene, andpolyparaphenylenevinylene. Examples of a method of producing anelectrode include a sputtering method, an evaporation method, a printingmethod from a solution or a paste, an inkjet method, and a dippingmethod. In addition, an electrode material is preferably any of theabove materials that have low electrical resistance at a contact surfacewith the semiconductor layer.

The insulating layer 8 is not limited as long as the layer formed of theorganic semiconductor can be uniformly applied to the layer, but theinsulating layer is preferably one having a high dielectric constant andlow conductivity. Examples of a material for the insulating layerinclude: inorganic oxides and nitrides such as silicon oxide, siliconnitride, aluminum oxide, titanium oxide, and tantalum oxide;polyacrylate; polymethacrylate; polyethylene terephthalate; polyimide;and polyether. Of those materials for the insulting layer, a materialhaving high surface smoothness is preferable.

A field effect transistor structure in the present invention may be anyone of a top contact electrode type, a bottom contact electrode type,and a top gate electrode type. In addition, the structure is not limitedto a horizontal type structure, and may be a vertical type structure(structure in which one of a source electrode and a drain electrode ispresent on the surface of an organic semiconductor layer on the side ofa base material and the other is present on the surface of the organicsemiconductor layer on the side opposite to the base material).

EXAMPLES Synthesis Example 1 Step (1)

2,4-pentanedione (205.4 ml, 2.0 mol), acetone (100 ml), n-butyl bromide(54 ml, 0.5 mol), and potassium carbonate (34.55 g, 0.25 mol) were fedinto a reaction vessel, air in the vessel was replaced with nitrogen,and reflux was carried out for 48 hours. The resultant solid wasfiltered out, and the solvent was distilled off by means of anevaporator. After that, unreacted 2,4-pentanedione was distilled offunder reduced pressure by means of a diaphragm. Then, the remainder wasdistilled in a vacuum to yield 3-n-butyl 2,4-pentanedione (43.25 g, 55%yield).

Step (2)

Benzyl acetoacetate (97 ml, 560 mmol) and acetic acid (81 ml) were fedinto a reaction vessel. Then, a solution of sodium nitrite (37.8 g) inwater (115 ml) was dropwise added into the mixture at 10° C. or lower.After the dropping, the mixture was stirred for 3 hours at roomtemperature. A solution of 3-n-butyl 2,4-pentanedione (43.16 g, 280mmol) obtained in Step (1) in acetic acid (45 ml), a mixture of zincpowder (36.6 g) and sodium acetate (25.9 g), and the above solution werefed into another vessel at 60° C. or lower, and was stirred at 80° C.for 1 hour. After that, the reaction solution was poured into ice water(1.12 L), and the resultant precipitate was filtered and washed withwater. The precipitate was dissolved in chloroform and washed withwater, a saturated aqueous solution of sodium bicarbonate, and asaturated salt solution. The organic layer was dried over anhydroussodium sulfate, concentrated, and distilled under reduced pressure bymeans of a diaphragm to remove an excess liquid. The remainder waspurified by means of silica gel column chromatography (EtOAc/Hexane) andrecrystallized (MeOH) to yield 4-n-butyl-3,5-dimethylpyrrole benzylester(22.92 g, 24% yield).

Step (3)

Acetic acid (200 ml) and acetic anhydride (3.09 ml) were fed into areaction vessel. 4-n-butyl-3,5-dimethylpyrrole benzylester (8.56 g, 30mmol) was dissolved into the mixture, and then lead tetraacetate (15.38g, 31.5 mmol) was slowly added to the solution. After the mixture hadbeen stirred for 2 hours, and the reaction solution was poured into theice water. The produced precipitate was filtered, and was thoroughlywashed with water. The precipitate was dissolved into chloroform, andwas washed with water, a saturated aqueous solution of sodiumbicarbonate, and a saturated salt solution. The organic layer was driedover anhydrous sodium sulfate, concentrated under reduced pressure, andsubjected to trituration with hexane to yield benzyl5-acetoxymethyl-4-n-butyl-3-methylpyrrole-2-carboxylate (8.93 g, 87%yield).

Step (4)

Air in a reaction vessel was replaced with nitrogen, and 1-nitropropane(8.93 ml, 100 mmol) and dehydrated tetrahydrofuran (dry-THF) (50 ml)were added to the vessel. Then, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)(1.5 ml, 10 mmol) was added to the mixture. After that, propionaldehyde(4.68 ml, 100 mmol) was added to the mixture while being was cooled onan ice bath. After the mixture had been stirred at room temperature for10 hours, ethyl acetate (100 ml) was added to the mixture, and waswashed with dilute hydrochloric acid, water, and a saturated saltsolution, and the organic layer was dried over anhydrous sodium sulfateand concentrated under reduced pressure, whereby 4-hydroxy-3-nitrohexanewas obtained (12.33 g, 84% yield).

Step (5)

4-hydroxy-3-nitrohexane (14.7 g, 100 mmol), acetic anhydride (14.8 ml,157.3 mmol), chloroform (50 ml), and several drops of concentratedsulfuric acid were fed into a reaction vessel, and the mixture wasstirred at room temperature for 10 hours. After the completion of thereaction, chloroform (50 ml) was added, and washed with water, a 5%aqueous solution of sodium bicarbonate, and a saturated salt solution.The organic layer was dried over anhydrous sodium sulfate andconcentrated under reduced pressure to yield 4-acetoxy-3-nitrohexane(16.3 g, 86% yield).

Step (6)

After 4-acetoxy-3-nitrohexane (11.34 g, 60 mmol) had been added to areaction vessel, air in the vessel was replaced with nitrogen, anddry-THF (150 ml) and ethyl isocyanoacetate (7.28 ml, 66 mmol) wereadded. Then, DBU (20.76 ml, 144 mmol) was slowly dropwise added whilebeing cooled on an ice bath, and stirred at room temperature for 12hours. After the completion of the reaction, 1 N hydrochloric acid wasadded, and extracted with chloroform, and the extract was washed withwater and a saturated salt solution. The organic layer was dried overanhydrous sodium sulfate and concentrated under reduced pressure. Afterthat, the concentrated product was purified by means of silica gelcolumn chromatography to yield ethyl 3,4-diethylpyrrole-2-carboxylate(10.97 g, 94% yield).

Step (7)

Ethyl 3,4-diethylpyrrole-2-carboxylate obtained in Step (6) (2.056 g,10.53 mmol), ethylene glycol (100 ml), and potassium hydroxide (3.5 g)were placed in a light-shielded reaction vessel equipped with a refluxcondenser. Then, the inside of the reaction vessel was replaced withnitrogen and the mixture was stirred at 160° C. for 2.5 hours. Afterthat, the reaction solution cooled to room temperature was poured intoice water, and extracted with ethyl acetate, and the extract was washedwith an aqueous solution of sodium bicarbonate, water, and a saturatedsalt solution. The organic layer was dried over anhydrous sodium sulfateand concentrated under reduced pressure, thereby to obtain3,4-diethylpyrrole. Again, 3,4-diethylpyrrole obtained by this reaction,benzyl-5-acetoxymethyl-4-n-butyl-3-methylpyrrole-2-carboxylate obtainedin Step (3) (7.21 g, 21 mmol), acetic acid (10 ml), and ethanol (150 ml)were fed into a light-shielded reaction vessel equipped with a refluxcondenser, and was refluxed for 18 hours. After the reflux, theresultant was cooled to room temperature, ethanol (50 ml) was added, andwas left standing at 0° C. for 5 hours. The precipitated crystal wasfiltered out and thoroughly washed with ethanol to yield2,5-bis(5-benzylcarbonyl-3-n-butyl-4-methyl-2-pyrroylmethyl)-3,4-dimethyl-1H-pyrrole(5.25 g, 72% yield).

Step (8)

Palladium carbon (Pd/C) (0.5 g) and dry-THF (20 ml) were fed into athree-necked flask, and air in the flask was replaced with hydrogen, andstirring was carried out for 30 minutes. A solution prepared bydissolving2,5-bis(5-benzylcarbonyl-3-n-butyl-4-methyl-2-pyrroylmethyl)-3,4-dimethyl-1H-pyrrole(2.09 g, 3.03 mmol) in dry-THF (30 ml) was slowly dropwise added intothe mixture, and was stirred at room temperature overnight. After thestirring, the solution was subjected to Celite filtration. The filtratewas concentrated under reduced pressure, shielded from light, and cooledon an ice bath in a nitrogen atmosphere. Trifluoro acetate (TFA) (5 ml)was dropwise added, and was stirred for 10 minutes. After that,trimethyl orthoformate (CH(OMe)₃) (10 ml) was slowly dropwise added, andwas stirred at 0° C. for 1 hour. After the solution had been neutralizedwith 1 M NaOH (which had been diluted with a solution of MeOH/H₂O=1/1),the resultant was poured into ice water. As a result, a brown solidprecipitated. The solid was filtered out, washed with water, and rinsedwith hexane to yield2,5-bis(5-formyl-3-n-butyl-4-methyl-2-pyrroylmethyl)-3,4-diethyl-1H-pyrrole(1.94 g, 60% yield).

Step (9)

1,4-cyclohexadiene (73.77 ml, 0.78 mmol) was placed in a three-neckedflask, stirred, and cooled to −45° C. A solution of bromine (122.5 g,0.77 mmol) in hexane (350 ml) was slowly dropwise added to the flaskover 4 hours or longer. After the completion of the dropping, thereaction solution was returned to room temperature and filtrated, andthe filtrate was concentrated and dried under reduced pressure, whereby4,5-dibromo-1-cyclohexene was obtained (146.5 g, 79%).

Step (10)

The compound obtained in Step (9) (80.5 g, 338 mmol), water (500 ml),acetone (250 ml), and N-methylmorpholine (45.5 g, 389 mmol) were placedin a reaction vessel, and was stirred. OsO₄ (1 g) was added to themixture, and was vigorously stirred for 24 hours. After the completionof the reaction, a suspension of NaHSO₃ (50 g) and Florisil (250 g) inwater (100 ml) was added to the reaction solution, and was stirred for10 minutes. After that, insoluble matter was removed by celitefiltration, and 5% HCl was added to the filtrate until the pH of thefiltrate became 3. Upon confirming that the pH had reached 3, andacetone was removed under reduced pressure. Organic matter was extractedfrom the remainder with ethyl acetate, dried over sodium sulfate, andconcentrated under reduced pressure. The precipitated crystals werefiltrated, and was then recrystallized with methylene chloride, whereby4,5-dibromo-1,2-cyclohexanediol was obtained (64.6 g, 70%).

Step (11)

The compound obtained in Step (10) (20.6 g, 75.62 mmol) was placed in areaction vessel, and air in the vessel was replaced with nitrogen.2,2-dimethoxypropane (12.92 ml) and p-toluenesulfonic acid (0.9 g) wereadded to the vessel, and the mixture was stirred for 3 hours. After thecompletion of the reaction had been confirmed, the mixture was filtratedthrough activated alumina, and the filtrate was concentrated underreduced pressure, whereby5,6-dibromo-2,2-dimethylhexahydro-1,3-benzodioxol was obtained (17.1 g,72%).

Step (12)

The compound obtained in Step (11) was placed in a reaction vessel, andair in the vessel was replaced with nitrogen. After that, the compoundwas dissolved in dehydrated toluene (116 ml). Distilled DBU (6.0 ml,40.1 mmol) was added to the solution, and the mixture was refluxed for 6hours. After the reaction product had been filtrated, sodium hydrogencarbonate was added to the filtrate, and the organic layer was driedover magnesium sulfate, whereby2,2-dimethyl-3a,7a-dihydrobenzo[1.3]dioxol was obtained. The compoundwas used in the next reaction without being further purified.

Step (13)

Trans-1,2-bis(phenylsulfonyl)ethylene (1.37 g, 4.45 mmol) was added to asolution of the compound obtained in Step (12) in toluene, and air in avessel containing the mixture was replaced with nitrogen. After havingbeen refluxed for 8 hours, the mixture was concentrated under reducedpressure. The resultant reaction product was purified by silica gelchromatography (50% EtOAc/Hexane), whereby10,11-bis(phenylsulfonyl)-4,4-dimethyl-3,5-dioxa-tricyclo[5.2.2.0^(2.6)]undec-8-enewas obtained (2.0 g, 98%).

Step (14)

The compound obtained in Step (13) (4.0 g, 8.7 mmol) was placed in areaction vessel, and air in the vessel was replaced with nitrogen. Afterthat, the compound was dissolved in tetrahydrofuran (24 ml). Ethylisocyanoacetate (1.3 ml, 12.2 mmol) and 1M t-BuOK (tetrahydrofuransolution) (21.7 ml, 21.7 mmol) were added to the solution on an icebath. Thereafter, the mixture was stirred at room temperature for 18hours. A 10% HCl aqueous solution (24.4 ml) and 160 ml of water wereadded to the reaction solution, and then the mixture was extracted withethyl acetate, washed with a saturated salt solution, dried overanhydrous sodium sulfate, and concentrated under reduced pressure. Theresultant reaction product was purified by silica gel chromatography,whereby a target product represented by a general formula (a) wasobtained (2.4 g, 95%).

Step (15)

The compound obtained in Step (14) (1 g, 3.45 mmol), ethylene glycol (50ml), and potassium hydroxide (0.8 g) were placed in a reaction vessel,and air in the vessel was replaced with nitrogen. After that, themixture was stirred at 175° C. for 5 hours. Thereafter, the reactionsolution was returned to room temperature and poured into water, and wasthen extracted with ethyl acetate, washed with water and a saturatedsalt solution, and purified by silica gel chromatography, whereby atarget product represented by a general formula (b) was obtained (0.52g, 70%).

Step (16)

Methylene chloride (300 ml) and trichloroacetic acid (8.43 g) wereplaced into a reaction vessel, and air in the vessel was replaced withnitrogen. A liquid prepared by dissolving the compound synthesized inStep (8) (0.79 g, 1.7 mmol) and the compound synthesized in Step (15)(0.37 g, 1.7 mmol) in methylene chloride (125 ml) was dropwise added tothe mixture over 15 minutes. After that, the mixture was stirred at roomtemperature for 20 hours, and was then neutralized with triethylamine.Chloranil was added to the neutralized product, and the mixture wasstirred for 2.5 hours. The reaction solution was poured into water, andthe mixture was extracted with methylene chloride, washed with asaturated sodium bicarbonate solution and water, dried over anhydroussodium sulfate, concentrated under reduced pressure, and purified byalumina column chromatography, whereby a compound represented by ageneral formula (c) was obtained (0.18 g, 16%).

Step (17)

The compound obtained in Step (16) was placed in a reaction vessel anddissolved in tetrahydrofuran, and 6N HCl was added to the solution.After that, the mixture was stirred at room temperature. Thereafter, thereaction solution was poured into water, and the mixture was extractedwith ethyl acetate, washed with water, dried over anhydrous sodiumsulfate, and concentrated under reduced pressure, whereby a compoundrepresented by a general formula (d) was obtained.

Step (18)

Air in a reaction vessel was replaced with nitrogen, and dimethylsulfoxide (0.8 ml) and methylene chloride (2.1 ml) were added to thevessel. After that, trifluoroacetic anhydride (1.0 ml) was dropwiseadded to the mixture at −60° C., and was stirred for 10 minutes.Thereafter, a solution of the compound represented by the generalformula (d) obtained in Step (17) (39 mg, 0.063 mmol) in dimethylsulfoxide was dropwise added to the mixture at −60° C., and was stirredfor 1.5 hours. Then, triethylamine (2.5 ml) was added to the mixture at−60° C., and was stirred for an additional 1.5 hours. After that, thereaction solution was returned to room temperature and poured into a 10%HCl aqueous solution, and the mixture was extracted with methylenechloride, washed with water, dried over anhydrous sodium sulfate,concentrated under reduced pressure, and purified by silica gelchromatography, whereby a compound represented by a general formula (e)was obtained (24 mg, 62% yield).

¹H NMR (CDCl₃) δ=10.13, 7.39, 6.14, 4.15, 4.01, 3.71, 2.31, 1.90, 1.73,1.11, −3.89

Infrared absorption spectrum (ATR) cm⁻¹: 1,739 (CO)

Mass spectrum (MALDI-TOF-MS) m/z: 556.358, 613.441

Synthesis Example 2 Step (1)

The compound represented by the general formula (a) synthesized in Step(14) of Synthesis Example 1 (0.29 g, 1.0 mmol) was placed in a reactionvessel, and air in the vessel was replaced with nitrogen. The compoundwas dissolved in anhydrous tetrahydrofuran (5.0 ml), and the reactionvessel was immersed in an ice bath. Lithium aluminum hydride (0.11 g,3.0 mmol) was added to the solution, the ice bath was removed, and themixture was stirred at room temperature for 1 hour. After the completionof the reduction, a saturated salt solution (20 ml) was added to themixture, insoluble matter was subjected to celite filtration, and theremainder was extracted with chloroform and dried over anhydrous sodiumsulfate. p-toluenesulfonic acid (0.08 g) was added to the solution, andthe mixture was stirred for 1 day. Further, chloranil (0.22 g, 0.91mmol) was added to the mixture, and was stirred for an additional 1 day.After the completion of the reaction, the reaction solution was washedwith a 1% sodium thiosulfate aqueous solution and a saturated saltsolution, dried over anhydrous sodium sulfate, concentrated underreduced pressure, purified by silica gel column chromatography, andrecrystallized, whereby a compound represented by a general formula (f)was obtained (0.05 g, 21%).

Step (2)

The compound represented by the general formula (f) synthesized in Step(1) of Synthesis Example 2 was placed into a reaction vessel, and air inthe vessel was replaced with nitrogen. After that, the compound wasdissolved in tetrahydrofuran. A 1M HCl aqueous solution was added in anamount equal to that of tetrahydrofuran to the solution, and the mixturewas stirred for 4 hours. After the completion of the reaction, themixture was extracted with ethyl acetate, washed with water and asaturated salt solution, dried over anhydrous sodium sulfate,concentrated under reduced pressure, purified by silica gelchromatography, and recrystallized, whereby a compound represented by ageneral formula (g) was obtained (84%).

Step (3)

Air in a reaction vessel was replaced with nitrogen, and dimethylsulfoxide (0.8 ml) and methylene chloride (5.0 ml) were added to thevessel. After that, trifluoroacetic anhydride (1.2 ml) was dropwiseadded to the mixture at −60° C., and was stirred for 10 minutes.Thereafter, a solution of the compound represented by the generalformula (g) obtained in Step (2) of Synthesis Example 2 (50 mg, 0.067mmol) in dimethyl sulfoxide (0.5 ml) was dropwise added to the mixtureat −60° C., and was stirred for 1.5 hours. Then, triethylamine (2.7 ml)was added to the mixture at −60° C., and was stirred for an additional1.5 hours. After that, the reaction solution was returned to roomtemperature and poured into a 10% HCl aqueous solution, and wasextracted with methylene chloride, washed with water and a saturatedsalt solution, dried over anhydrous sodium sulfate, concentrated underreduced pressure, and triturated with ethyl acetate, whereby a compoundrepresented by a general formula (h) was obtained (15 mg, 30%).

¹H NMR (CDCl₃) δ=9.99, 7.51, 6.20

Infrared absorption spectrum (ATR) cm⁻¹: 1,728 (CO)

Mass spectrum (MALDI-TOF-MS) m/z: 510.291 (only the mass of a benzo bodywas observed because a carbonyl group was eliminated during ionization).

Step (4)

The compound represented by the general formula (f) and zinc acetatewere allowed to react with each other, whereby a zinc complex wasobtained. The resultant compound (1.0 g), THF (100 ml), and 1N HCl (100ml) were mixed, and air in a reaction vessel containing the mixture wasreplaced with nitrogen. After that, the mixture was stirred at 65° C.for 3 hours and returned to room temperature. The reaction solution wasconcentrated, and then the concentrate was dissolved in ethanol. Thesolution was passed through sodium hydrogen carbonate so as to beconcentrated again. After that, the resultant compound was purified bysilica gel column chromatography, whereby a zinc complex of the compoundrepresented by the general formula (g) was quantitatively obtained.

Step (5)

Air in a reaction vessel was replaced with nitrogen, and dimethylsulfoxide (0.93 ml) and methylene chloride (5.4 ml) were added to thevessel. After that, trifluoroacetic anhydride (1.3 ml) was dropwiseadded to the mixture at −60° C., and was stirred for 10 minutes. Afterthat, a solution of the zinc complex of the compound represented by thegeneral formula (g) obtained in Step (4) of Synthesis Example 2 (59 mg,0.072 mmol) in dimethyl sulfoxide (1.0 ml) was dropwise added to themixture at −60° C., and was stirred for 1.5 hours. After that,triethylamine (3.0 ml) was added to the mixture at −60° C., and wasstirred for an additional 1.5 hours. After that, the reaction solutionwas returned to room temperature and poured into a 10% aqueous solutionof HCl, and the mixture was extracted with methylene chloride, washedwith water and a saturated salt solution, dried over anhydrous sodiumsulfate, concentrated under reduced pressure, and triturated with ethylacetate, whereby a zinc complex of the compound represented by thegeneral formula (h) was obtained (16 mg, 28%).

¹H NMR (CDCl₃) δ=10.17 (4H, m), 7.45 (8H, m), 6.18 (8H, m)

Infrared absorption spectrum (ATR) cm⁻¹: 1,728 (CO)

Mass spectrum (MALDI-TOF-MS) m/z: 510.329 (only the mass of a benzo bodywas observed because a carbonyl group and zinc as a central metal wereeliminated during ionization).

Step (6)

The compound represented by the general formula (h) and copper acetatewere allowed to react with each other, whereby a copper complex wasquantitatively obtained.

Infrared absorption spectrum (ATR) cm⁻¹: 1,728 (CO)

Mass spectrum (MALDI-TOF-MS) m/z: 510.303 (only the mass of a benzo bodywas observed because a carbonyl group and copper as a central metal wereeliminated during ionization).

Synthesis Example 3 Step (1)

Phosphorus pentoxide (17 g, 60 mmol) was placed in a three-necked flask,and air in the flask was replaced with nitrogen. In the presence ofP₂O₅, sulfolane distilled under reduced pressure (70 ml) was placed inthe flask. Acetylene dicarboxyamide (5 g, 45 mmol) suspended insulfolane was dropwise added to the mixture at 110° C. and 12 Torr over30 minutes or more.

After the completion of the dropping, the temperature of the reactionliquid was set at 120° C., where produced dicyanoacetylene wasvaporized, and hence, was recovered while being cooled in a dryice-acetone bath (0.85 g, 25%).

Step (2)

Air in an egg plant flask containing dicyanoacetylene (0.38 g, 5.0 mmol)was replaced with nitrogen, and toluene was added to dissolvedicyanoacetylene. 2,2-dimethyl-3a,7a-dihydrobenzo[1.3]dioxol (0.31 g,2.0 mmol) was added to the solution, and was stirred at room temperatureovernight. After that, the resultant was washed with water and asaturated salt solution, dried over anhydrous sodium sulfate,concentrated under reduced pressure, and purified by silica gel columnchromatography, whereby a compound represented by a general formula (1)was obtained (0.46 g, 40%).

Step (3)

Magnesium (3.1 mg), dehydrated butanol (4.4 ml), and a slight amount ofiodine were placed in a reaction vessel whose inside had been replacedwith nitrogen, and stirred at 120° C. for 3 hours. The resultantsolution (1.2 ml) was added to a reaction vessel which contained thecompound represented by the general formula (1) obtained in Step (2) ofSynthesis Example 3 (20 mg, 0.08 mmol) and whose inside had beenreplaced with nitrogen, and the mixture was stirred at 120° C. for 2days. The reaction solution was poured into a solution containing waterand methanol in a ratio of 1:1, and was extracted with chloroform. Theorganic layer was washed with water and a saturated salt solution, driedover anhydrous sodium sulfate, concentrated under reduced pressure, andseparated by alumina column chromatography, whereby a compoundrepresented by a general formula (j) was obtained (7% yield).

Step (4)

The compound represented by the general formula (j) obtained in Step (3)of Synthesis Example 3 is placed in a reaction vessel, air in the vesselis replaced with nitrogen, and the compound is dissolved intetrahydrofuran. 1N hydrochloric acid is added to the solution, and themixture is stirred at room temperature. After the completion of thereaction, the mixture is washed with a saturated salt solution, and theorganic layer is dried over anhydrous sodium sulfate, concentrated underreduced pressure, purified by silica gel column chromatography, andrecrystallized, whereby a compound represented by a general formula (k)can be obtained.

Step (5)

Air in a reaction vessel is replaced with nitrogen, and dimethylsulfoxide and methylene chloride are added to the vessel. After that,trifluoroacetic anhydride is dropwise added to the mixture at −60° C.,and stirred for 10 minutes. After that, a solution of the compoundrepresented by the general formula (k) obtained in Step (4) of SynthesisExample 3 in dimethyl sulfoxide is dropwise added to the mixture at −60°C., and stirred for 1.5 hours. Thereafter, triethylamine is added to themixture at −60° C., and stirred for an additional 1.5 hours. Then, thereaction solution is returned to room temperature, poured into a 10% HClaqueous solution, extracted with methylene chloride, washed with waterand a saturated salt solution, dried over anhydrous sodium sulfate,concentrated under reduced pressure, and purified by silica gelchromatography, whereby a compound represented by a general formula (1)can be obtained.

Synthesis Example 4

A reaction solution containing pentacene (0.46 g, 1.6 mmol) andthiophosgene (2 ml) was subjected to reaction at 65° C. for 6 hours. Thereaction solution was cooled to room temperature, and dichloromethane (2ml) was added to the reaction solution. After that, the mixture wasfiltrated so that unreacted pentacene was removed, and the filtrate wasconcentrated under reduced pressure. After the concentration, 40 ml oftoluene were added to the concentrate, and the mixture was concentratedunder reduced pressure so that unreacted thiophosgene was removed. Theresultant product was purified by silica gel column chromatography,whereby a compound represented by a general formula (16) was obtained(40% yield).

Preparation of Resin Solution a

Resin Solution a was prepared by dissolving 1.0 g of commerciallyavailable flaky methyl silsesquioxane (MSQ) (manufactured by SHOWA DENKOK.K.; trade name: GR650) in a mixed solvent composed of 49.5 g ofethanol and 49.5 g of 1-butanol.

Preparation of Resin Solution b

1.0 g of methyltrimethoxysilane was completely dissolved in a mixedsolvent composed of 49.5 g of ethanol and 49.5 g of 1-butanol. 0.83 g ofdistilled water and 0.05 g of formic acid were added to the solution,and stirred at room temperature for 48 hours, whereby Silica Sol (ResinSolution) b was prepared.

Example 1

FIG. 1 shows the structure of a top electrode type field effecttransistor in this example.

First, a highly doped N-type silicon substrate was defined as the gateelectrode 1. A silicon oxide film having a thickness of 500 nm (5,000 Å)obtained by thermally oxidizing the surface layer of the siliconsubstrate was defined as the gate insulating layer 2. Next, ResinSolution a was applied to the surface of the insulating layer by a spincoating method (at the number of revolutions of 5,000 rpm). Next, thecoating film was transferred to a hot plate, and was heated at 100° C.for 5 minutes and at 220° C. for 30 minutes. Thus, the A layer 3(polysiloxane layer) was formed.

Next, a 1.0 wt % solution of the compound represented by the generalformula (e) synthesized in Synthesis Example 1 in chloroform was appliedonto the substrate on which the A layer 3 had been thus formed by a spincoating method at the number of revolutions of 900 rpm. Thus, a coatingfilm was formed. Further, the substrate on which the coating film hadbeen thus formed was mounted on a hot plate set at 150° C., and wasirradiated with light from a metal halide lamp manufactured by NIPPONP.I. CO., LTD. (PCS-UMX250) through a heat absorbing filter and a bluefilter for 5 minutes. Thus, the B layer 6 (organic semiconductor layer)was formed.

Au was vapor-deposited onto the B layer 6 by using a mask, whereby thesource electrode 4 and the drain electrode 5 were formed. The conditionsunder which the electrodes were produced were as follows: a degree ofvacuum in a vacuum device chamber was 1×10⁻⁶ torr, and the temperatureof the substrate was room temperature. The electrodes thus obtained eachhad a thickness of 100 nm.

A field effect transistor having a channel length L of 50 μm and achannel width W of 3 mm was produced by the foregoing procedure. TheV_(d)−I_(d) and V_(g)−I_(d) curves of the produced transistor weremeasured with a parameter analyzer 4156C (trade name) manufactured byAgilent.

A mobility μ (cm²/Vs) of the transistor was calculated in accordancewith the following equation (1).I _(d)=μ(CiW/2L)×(V _(g) −V _(th))²  (Eq. 1)

In the equation, Ci represents the electrostatic capacity of the gateinsulating layer per unit area (F/cm²), W and L represent the channelwidth (mm) and the channel length (μm) shown in the example,respectively, and I_(d), V_(g), and V_(th) represent a drain current(A), a gate voltage (V), and a threshold voltage (V), respectively. Inaddition, a ratio of I_(d) at V_(g) of −80 V to I_(d) at V_(g) of 0 V atV_(d) of −80 V was defined as an on/off ratio. The field effect mobilitycalculated from the obtained results was 1.8×10⁻³ cm²/Vs. In addition,the on/off ratio was 3.1×10³. In addition, the substrate of thetransistor was subjected to CuKα X-ray diffraction measurement. As aresult, a diffraction peak was observed, and it was confirmed that thesubstrate had satisfactory crystallinity.

Example 2

A highly doped N-type silicon substrate was defined as a gate electrode.A silicon oxide film having a thickness of 500 nm (5,000 Å) obtained bythermally oxidizing the surface layer of the silicon substrate wasdefined as a gate insulating layer. Next, a 1.0 wt % solution of thecompound represented by the general formula (e) synthesized in SynthesisExample 1 in chloroform was applied onto the substrate by a spin coatingmethod at the number of revolutions of 900 rpm. Thus, a coating film wasformed. Further, the substrate on which the coating film had been thusformed was mounted on a hot plate set at 150° C., and was irradiatedwith light from a metal halide lamp manufactured by NIPPON P.I. CO.,LTD. (PCS-UMX250) through a heat absorbing filter and a blue filter for5 minutes. Thus, an organic semiconductor layer was formed.

Au was vapor-deposited onto the organic semiconductor layer by using amask, whereby a source electrode and a drain electrode were formed. Theconditions under which the electrodes were produced were as follows: adegree of vacuum in a vacuum device chamber was 1×10⁻⁶ torr, and thetemperature of the substrate was room temperature.

The electrodes thus obtained each had a thickness of 100 nm. A fieldeffect transistor having a channel length L of 50 μm and a channel widthW of 3 mm was produced by the foregoing procedure, and was evaluated forits electrical characteristics in the same manner as in Example 1. Thetransistor had a field effect mobility of 1.0×10⁻⁵ cm²/Vs. In addition,the transistor had an on/off ratio of 3.6×10².

Example 3

A highly doped N-type silicon substrate was defined as a gate electrode.A silicon oxide film having a thickness of 500 nm (5,000 Å) obtained bythermally oxidizing the surface layer of the silicon substrate wasdefined as a gate insulating layer. Next, a 1.0 wt % solution of thecompound represented by the general formula (16) synthesized inSynthesis Example 4 in chloroform was applied onto the substrate by aspin coating method at the number of revolutions of 1,000 rpm. Thus, acoating film was formed. Further, the substrate on which the coatingfilm had been thus formed was mounted on a hot plate set at 120° C., andwas irradiated with light from a UV light source manufactured byHOYA-SCHOTT (EX250) through a heat absorbing filter for 1 minute. Thus,an organic semiconductor layer was formed. Au was vapor-deposited ontothe organic semiconductor layer by using a mask, whereby a sourceelectrode and a drain electrode were formed. The conditions under whichthe electrodes were produced were as follows: a degree of vacuum in avacuum device chamber was 1×10⁻⁶ torr, and the temperature of thesubstrate was room temperature. The electrodes thus obtained each had athickness of 100 nm. A field effect transistor having a channel length Lof 50 μm and a channel width W of 3 mm was produced by the foregoingprocedure. The V_(d)−I_(d) and V_(g)−I_(d) curves of the producedtransistor were measured with a parameter analyzer 4156C (trade name)manufactured by Agilent.

The mobility μ (cm²/Vs) of the transistor was calculated in accordancewith the following equation (1).I _(d)=μ(CiW/2L)×(V _(g) −V _(th))²  (Eq. 2)

In the equation, Ci represents the electrostatic capacity of the gateinsulating layer per unit area (F/cm²), W and L represent the channelwidth (mm) and the channel length (μm) shown in the example,respectively, and I_(d), V_(g), and V_(th) represent a drain current(A), a gate voltage (V), and a threshold voltage (V), respectively. Inaddition, a ratio I_(d) at V_(g) of −80 V to I_(d) at V_(g) of 0 V atV_(d) of −80 V was defined as an on/off ratio. The field effect mobilitycalculated from the obtained results and the on/off ratio are shown inTable 1.

Example 4

A highly doped N-type silicon substrate was defined as a gate electrode.A silicon oxide film having a thickness of 500 nm (5,000 Å) obtained bythermally oxidizing the surface layer of the silicon substrate wasdefined as a gate insulating layer. Next, the compound represented bythe general formula (16) synthesized in Synthesis Example 4 and ethanolwere mixed in a molar ratio (ethanol/general formula (16)) of 7.8, and a1.0 wt % solution was prepared by adding chloroform to the mixture. Thesolution was applied onto the substrate by a spin coating method at thenumber of revolutions of 1,000 rpm. Thus, a coating film was formed.Further, the substrate on which the coating film had been thus formedwas mounted on a hot plate set at 140° C., and was heated for 30minutes. Thus, an organic semiconductor layer was formed. Au wasvapor-deposited onto the organic semiconductor layer by using a mask,whereby a source electrode and a drain electrode were formed. Theconditions under which the electrodes were produced were as follows: adegree of vacuum in a vacuum device chamber was 1×10⁻⁶ torr, and thetemperature of the substrate was room temperature. The electrodes thusobtained each had a thickness of 100 nm. A field effect transistorhaving a channel length L of 50 μm and a channel width W of 3 mm wasproduced by the foregoing procedure, and was evaluated for itselectrical characteristics. However, the transistor did not showtransistor characteristics. Table 1 shows the results.

Example 5

A transistor was produced in the same manner as in Example 4 exceptthat: the temperature of the hot plate was set at 200° C.; and theorganic semiconductor layer was formed with the time period for whichthe substrate was heated changed to 1 minute, and the transistor wasevaluated for its electrical characteristics. Table 1 shows the results.

Example 6

A highly doped N-type silicon substrate was defined as a gate electrode.A silicon oxide film having a thickness of 500 nm (5,000 Å) obtained bythermally oxidizing the surface layer of the silicon substrate wasdefined as a gate insulating layer. Next, the compound represented bythe general formula (16) synthesized in Synthesis Example 4 and ethanolwere mixed in a molar ratio (ethanol/general formula (16)) of 7.8, and a1.0 wt % solution was prepared by adding chloroform to the mixture. Thesolution was applied onto the substrate by a spin coating method at thenumber of revolutions of 1,000 rpm. Thus, a coating film was formed.Further, the substrate on which the coating film had been thus formedwas irradiated with light from a UV light source manufactured byHOYA-SCHOTT (EX250) through a heat absorbing filter at room temperaturefor 1 minute. Thus, an organic semiconductor layer was formed. Au wasvapor-deposited onto the organic semiconductor layer by using a mask,whereby a source electrode and a drain electrode were formed. Theconditions under which the electrodes were produced were as follows: adegree of vacuum in a vacuum device chamber was 1×10⁻⁶ torr, and thetemperature of the substrate was room temperature. The electrodes thusobtained each had a thickness of 100 nm. A field effect transistorhaving a channel length L of 50 μm and a channel width W of 3 mm wasproduced by the foregoing procedure, and was evaluated for itselectrical characteristics. Table 1 shows the results.

Example 7

A highly doped N-type silicon substrate was defined as a gate electrode.A silicon oxide film having a thickness of 500 nm (5,000 Å) obtained bythermally oxidizing the surface layer of the silicon substrate wasdefined as a gate insulating layer. Next, the compound represented bythe general formula (16) synthesized in Synthesis Example 4 and ethanolwere mixed in a molar ratio (ethanol/general formula (16)) of 7.8, and a1.0 wt % solution was prepared by adding chloroform to the mixture. Thesolution was applied onto the substrate by a spin coating method at thenumber of revolutions of 1,000 rpm. Thus, a coating film was formed.Further, the substrate on which the coating film had been thus formedwas mounted on a hot plate set at 120° C. and irradiated with light froma UV light source manufactured by HOYA-SCHOTT (EX250) through a heatabsorbing filter at room temperature for 1 minute. Thus, an organicsemiconductor layer was formed. Au was vapor-deposited onto the organicsemiconductor layer by using a mask, whereby a source electrode and adrain electrode were formed. The conditions under which the electrodeswere produced were as follows: a degree of vacuum in a vacuum devicechamber was 1×10⁻⁶ torr, and the temperature of the substrate was roomtemperature. The electrodes thus obtained each had a thickness of 100nm. A field effect transistor having a channel length L of 50 μm and achannel width W of 3 mm was produced by the foregoing procedure, and wasevaluated for its electrical characteristics. Table 1 shows the results.

Example 8

A transistor was produced in the same manner as in Example 7 except thatthe temperature of the hot plate was set at 130° C., and the transistorwas evaluated for its electrical characteristics. Table 1 shows theresults.

Example 9

A transistor was produced in the same manner as in Example 7 except thatthe temperature of the hot plate was set at 140° C., and the transistorwas evaluated for its electrical characteristics. Table 1 shows theresults.

Example 10

A transistor was produced in the same manner as in Example 7 except thatthe temperature of the hot plate was set at 180° C., and the transistorwas evaluated for its electrical characteristics. Table 1 shows theresults.

TABLE 1 Mobility (cm²/Vs) on/off Example 3 2.3 × 10⁻² 9.6 × 10³ Example4 — — Example 5 2.3 × 10⁻⁴ 3.7 × 10⁴ Example 6 6.2 × 10⁻⁵ 29 Example 75.0 × 10⁻² 1.9 × 10³ Example 8 9.0 × 10⁻² 4.2 × 10² Example 9 1.0 × 10⁻¹1.3 × 10² Example 10 1.5 × 10⁻⁴ 1.4 × 10³

Example 11

A 1.0 wt % solution of the compound represented by the general formula(16) in chloroform was prepared, and was applied onto a substrate by aspin coating method, whereby a film was formed.

Example 12

The compound represented by the general formula (16) and ethanol weremixed in a molar ratio (ethanol/general formula (16)) of 1.6, and a 1.0wt % solution was prepared by adding chloroform to the mixture. Thesolution was applied onto a substrate by a spin coating method, wherebya film was formed.

Example 13

A film was formed in the same manner as in Example 12 except that themolar ratio was changed to 7.8.

Example 14

The compound represented by the general formula (16) and ethanol weremixed in a molar ratio (ethanol/general formula (16)) of 5.7, and a 1.0wt % solution was prepared by adding chloroform to the mixture. Thesolution was applied onto a substrate by a spin coating method, wherebya film was formed.

Example 15

A film was formed in the same manner as in Example 14 except that themolar ratio was changed to 11.3.

Example 16

A film was formed in the same manner as in Example 14 except that themolar ratio was changed to 28.3.

Example 17

The compound represented by the general formula (16) and isopropylalcohol were mixed in a molar ratio (isopropyl alcohol/general formula(16)) of 5.9, and a 1.0 wt % solution was prepared by adding chloroformto the mixture. The solution was applied onto a substrate by a spincoating method, whereby a film was formed.

Example 18

The compound represented by the general formula (16) and acetonitrilewere mixed in a molar ratio (acetonitrile/general formula (16)) of 8.7,and a 1.0 wt % solution was prepared by adding chloroform to themixture. The solution was applied onto a substrate by a spin coatingmethod, whereby a film was formed.

Example 19

A 1.0 wt % solution of the compound represented by the general formula(16) in toluene was prepared, and was applied onto a substrate by a spincoating method, whereby a film was formed.

Example 20

The compound represented by the general formula (16) and ethanol weremixed in a molar ratio (ethanol/general formula (16)) of 6.7, and a 1.0wt % solution was prepared by adding toluene to the mixture. Thesolution was applied onto a substrate by a spin coating method, wherebya film was formed.

Example 21

The compound represented by the general formula (16) and 1-butanol weremixed in a molar ratio (1-butanol/general formula (16)) of 4.2, and a1.0 wt % solution was prepared by adding toluene to the mixture. Thesolution was applied onto a substrate by a spin coating method, wherebya film was formed.

Example 22

The compound represented by the general formula (16) and toluene weremixed in a molar ratio (toluene/general formula (16)) of 7.0, and a1.0-wt % solution was prepared by adding chloroform to the mixture. Thesolution was applied onto a substrate by a spin coating method, wherebya film was formed.

Films in Examples 11 to 22 each produced on a substrate 1.7 cm by 1.8 cmin size were compared with one another, and the average value of five 1mm square points on one substrate was evaluated on the basis of thefollowing three stages: A, B, and C. Table 2 shows the results.

(Evaluation for Film Quality)

A: The average number of pinholes is less than 15, and the averagediameter of the pinholes is less than 100 μm.

B: The average number of pinholes is 15 or more and less than 50, andthe average diameter of the pinholes is less than 100 μm.

C: The average number of pinholes is 50 or more, or the average diameterof the pinholes is 100 μm or more.

TABLE 2 Molar ratio (added solvent/general Film Main solvent Addedsolvent formula (16)) quality Example Chloroform — — C 11 ExampleChloroform Ethanol 1.6 B 12 Example Chloroform Ethanol 7.8 A 13 ExampleChloroform Methanol 5.7 A 14 Example Chloroform Methanol 11.3  A 15Example Chloroform Methanol 28.3  A 16 Example Chloroform Isopropanol5.9 A 17 Example Chloroform Acetonitrile 8.7 A 18 Example Toluene — — C19 Example Toluene Ethanol 6.7 A 20 Example Toluene 1-butanol 4.2 A 21Example Chloroform Toluene 7.0 B 22

Example 23

The compound represented by the general formula (e) was dissolved indeuterated chloroform, and the ¹H-NMR of the compound was measured,whereby it was confirmed that the compound had a structure representedby the general formula (e). The sample after the measurement wasirradiated with light from a metal halide lamp for 10 minutes. Afterthat, the ¹H-NMR of the sample was measured, whereby it was confirmedthat the sample was changed to a benzo body represented by a generalformula (31) obtained as a result of the elimination of a carbonyl groupfrom the structure represented by the general formula (e). FIGS. 4( a)and 4(b) show the NMR spectra of the benzo body.

Example 24

A solution of a zinc complex of the compound represented by the generalformula (h) in acetone was prepared, and was applied onto a quartzsubstrate by a spin coating method at the number of revolutions of 1,000rpm. The substrate on which a coating film had been thus formed wasirradiated with light from a metal halide lamp in the air at roomtemperature for 5 minutes. The fact that the conversion of the compoundinto tetrabenzoporphyrin was attained was confirmed by measuring the UVspectrum of the film. FIG. 3 shows the UV spectrum.

Comparative Example 1

A 1 wt % solution of a compound represented by the following generalformula (17) in chloroform was prepared, and was applied onto a quartzsubstrate by a spin coating method at the number of revolutions of 1,000rpm. Two substrates on each of which a coating film had been thus formedwere produced. One of the substrates was heated at 250° C., and theother was irradiated with light. The heated sample transformed intopentacene, whereas the sample irradiated with light did not change.

Comparative Example 2

Two substrates on each of which a coating film had been formed wereproduced in the same manner as in Comparative Example 1 except that acompound represented by the following general formula (18) was used. Oneof the substrates was heated at 200° C., and the other was irradiatedwith light from a metal halide lamp manufactured by NIPPON P.I. CO.,LTD. (PCS-UMX250). The heated sample did not change, whereas the sampleirradiated with light transformed into pentacene.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application Nos.2006-352555, filed Dec. 27, 2006, and 2007-232091 filed on Sep. 6, 2007which are hereby incorporated by reference herein in their entirety.

1. A compound represented by the following general formula (9):

where the B ring is represented by the following general formula (27),R₁₇ to R₂₂ are each independently one selected from the group consistingof a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, analkoxy group, an alkylthio group, an ester group, an aryl group, aheterocyclic group, and an aralkyl group, Z₁ to Z₄ are each selectedfrom the group consisting of a nitrogen atom and CR₆₀, and may beidentical to or different from one another, wherein R₆₀ is one selectedfrom the group consisting of a hydrogen atom and an aryl group, Mrepresents two hydrogen atoms, a metal atom, or a metal oxide, and eachpair of R₁₇ and R₁₈, R₁₉ and R₂₀, or R₂₁ and R₂₂ may be combinedtogether to form the B ring;

where R₅₄ to R₅₉ are each independently one selected from the groupconsisting of a hydrogen atom, an alkyl group, an alkoxy group, an arylgroup, a heterocyclic group, an aralkyl group, a phenoxy group, a cyanogroup, a nitro group, an ester group, a carboxyl group, and a halogenatom, R₅₈ and R₅₉ may be coupled with each other to form a five-memberedheterocyclic ring or a six-membered heterocyclic ring, and n₅ and n₆each independently represent an integer of 0 or more.
 2. A compoundaccording to claim 1, wherein all of Z₁ to Z₄ of the general formula (9)are represented by CH.
 3. A compound according to claim 1, wherein allof Z₁ to Z₄ of the general formula (9) are represented by a nitrogenatom.